Merge 10.3 into 10.4

23 files changed, 605 insertions, 588 deletions

diff --git a/storage/connect/myconn.cpp b/storage/connect/myconn.cpp
index 253c42bb002..6de5a73875c 100644
--- a/storage/connect/myconn.cpp
+++ b/storage/connect/myconn.cpp
@@ -879,7 +879,7 @@ MYSQL_FIELD *MYSQLC::GetNextField(void)
 PQRYRES MYSQLC::GetResult(PGLOBAL g, bool pdb)
   {
 	PCSZ         fmt;
-  char        *name, v;
+  char        *name, v= 0;
   int          n;
   bool         uns;
   PCOLRES     *pcrp, crp;
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index aa2f3805bd6..27a43f98a4f 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -1689,9 +1689,9 @@ innobase_srv_conc_enter_innodb(
 			   && thd_is_replication_slave_thread(trx->mysql_thd)) {
 			const ulonglong end = my_interval_timer()
 				+ ulonglong(srv_replication_delay) * 1000000;
-			while (srv_conc_get_active_threads()
-			       >= srv_thread_concurrency
-			       || my_interval_timer() >= end) {
+			while ((srv_conc_get_active_threads()
+			        >= srv_thread_concurrency)
+			       && my_interval_timer() < end) {
 				os_thread_sleep(2000 /* 2 ms */);
 			}
 		} else {
@@ -3923,14 +3923,12 @@ static int innodb_init_params()
 		DBUG_RETURN(HA_ERR_INITIALIZATION);
 	}
 
-	if (srv_n_log_files * srv_log_file_size
-	    >= 512ULL * 1024ULL * 1024ULL * 1024ULL) {
-		/* log_block_convert_lsn_to_no() limits the returned block
-		number to 1G and given that OS_FILE_LOG_BLOCK_SIZE is 512
-		bytes, then we have a limit of 512 GB. If that limit is to
-		be raised, then log_block_convert_lsn_to_no() must be
-		modified. */
-		ib::error() << "Combined size of log files must be < 512 GB";
+	if (srv_n_log_files * srv_log_file_size >= log_group_max_size) {
+		/* Log group size is limited by the size of page number.
+		Remove this limitation when fil_io() is not used for
+		recovery log io. */
+		ib::error() << "Combined size of log files must be < "
+			<< log_group_max_size;
 		DBUG_RETURN(HA_ERR_INITIALIZATION);
 	}
 
@@ -19279,7 +19277,7 @@ static MYSQL_SYSVAR_ULONG(log_buffer_size, srv_log_buffer_size,
 static MYSQL_SYSVAR_ULONGLONG(log_file_size, srv_log_file_size,
   PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "Size of each log file in a log group.",
-  NULL, NULL, 48 << 20, 1 << 20, 512ULL << 30, UNIV_PAGE_SIZE_MAX);
+  NULL, NULL, 48 << 20, 1 << 20, log_group_max_size, UNIV_PAGE_SIZE_MAX);
 /* OS_FILE_LOG_BLOCK_SIZE would be more appropriate than UNIV_PAGE_SIZE_MAX,
 but fil_space_t is being used for the redo log, and it uses data pages. */
 
diff --git a/storage/innobase/handler/handler0alter.cc b/storage/innobase/handler/handler0alter.cc
index 19c35c66885..3d8f068b188 100644
--- a/storage/innobase/handler/handler0alter.cc
+++ b/storage/innobase/handler/handler0alter.cc
@@ -56,6 +56,9 @@ Smart ALTER TABLE
 #include "row0sel.h"
 #include "ha_innodb.h"
 #include "ut0stage.h"
+#include "span.h"
+
+using st_::span;
 
 static const char *MSG_UNSUPPORTED_ALTER_ONLINE_ON_VIRTUAL_COLUMN=
 			"INPLACE ADD or DROP of virtual columns cannot be "
@@ -2682,20 +2685,22 @@ innobase_set_foreign_key_option(
 /*******************************************************************//**
 Check if a foreign key constraint can make use of an index
 that is being created.
+@param[in]	col_names	column names
+@param[in]	n_cols		number of columns
+@param[in]	keys		index information
+@param[in]	add		indexes being created
 @return useable index, or NULL if none found */
 static MY_ATTRIBUTE((nonnull, warn_unused_result))
 const KEY*
 innobase_find_equiv_index(
-/*======================*/
 	const char*const*	col_names,
-					/*!< in: column names */
-	uint			n_cols,	/*!< in: number of columns */
-	const KEY*		keys,	/*!< in: index information */
-	const uint*		add,	/*!< in: indexes being created */
-	uint			n_add)	/*!< in: number of indexes to create */
+	uint			n_cols,
+	const KEY*		keys,
+	span<uint>		add)
 {
-	for (uint i = 0; i < n_add; i++) {
-		const KEY*	key = &keys[add[i]];
+	for (span<uint>::iterator it = add.begin(), end = add.end(); it != end;
+	     ++it) {
+		const KEY*	key = &keys[*it];
 
 		if (key->user_defined_key_parts < n_cols
 		    || key->flags & HA_SPATIAL) {
@@ -2746,7 +2751,7 @@ no_match:
 Find an index whose first fields are the columns in the array
 in the same order and is not marked for deletion
 @return matching index, NULL if not found */
-static MY_ATTRIBUTE((nonnull(1,5), warn_unused_result))
+static MY_ATTRIBUTE((nonnull(1,4), warn_unused_result))
 dict_index_t*
 innobase_find_fk_index(
 /*===================*/
@@ -2754,10 +2759,8 @@ innobase_find_fk_index(
 	const char**		col_names,
 					/*!< in: column names, or NULL
 					to use table->col_names */
-	dict_index_t**		drop_index,
+	span<dict_index_t*>	drop_index,
 					/*!< in: indexes to be dropped */
-	ulint			n_drop_index,
-					/*!< in: size of drop_index[] */
 	const char**		columns,/*!< in: array of column names */
 	ulint			n_cols) /*!< in: number of columns */
 {
@@ -2766,21 +2769,14 @@ innobase_find_fk_index(
 	index = dict_table_get_first_index(table);
 
 	while (index != NULL) {
-		if (dict_foreign_qualify_index(
-			    table, col_names, columns, n_cols,
-			    index, NULL, true, 0,
-			    NULL, NULL, NULL)) {
-			for (ulint i = 0; i < n_drop_index; i++) {
-				if (index == drop_index[i]) {
-					/* Skip to-be-dropped indexes. */
-					goto next_rec;
-				}
-			}
-
-			return(index);
+		if (dict_foreign_qualify_index(table, col_names, columns,
+					       n_cols, index, NULL, true, 0,
+					       NULL, NULL, NULL)
+		    && std::find(drop_index.begin(), drop_index.end(), index)
+			   == drop_index.end()) {
+			return index;
 		}
 
-next_rec:
 		index = dict_table_get_next_index(index);
 	}
 
@@ -2926,7 +2922,7 @@ innobase_get_foreign_key_info(
 
 			index = innobase_find_fk_index(
 				table, col_names,
-				drop_index, n_drop_index,
+				span<dict_index_t*>(drop_index, n_drop_index),
 				column_names, i);
 
 			/* MySQL would add a index in the creation
@@ -2941,8 +2937,8 @@ innobase_get_foreign_key_info(
 			if (!index && !innobase_find_equiv_index(
 				    column_names, static_cast<uint>(i),
 				    ha_alter_info->key_info_buffer,
-				    ha_alter_info->index_add_buffer,
-				    ha_alter_info->index_add_count)) {
+				    span<uint>(ha_alter_info->index_add_buffer,
+					       ha_alter_info->index_add_count))) {
 				my_error(
 					ER_FK_NO_INDEX_CHILD,
 					MYF(0),
@@ -7184,8 +7180,8 @@ innobase_check_foreign_key_index(
 			    foreign->referenced_col_names,
 			    foreign->n_fields,
 			    ha_alter_info->key_info_buffer,
-			    ha_alter_info->index_add_buffer,
-			    ha_alter_info->index_add_count)) {
+			    span<uint>(ha_alter_info->index_add_buffer,
+				       ha_alter_info->index_add_count))) {
 
 			/* Index cannot be dropped. */
 			trx->error_info = index;
@@ -7219,8 +7215,8 @@ innobase_check_foreign_key_index(
 			    foreign->foreign_col_names,
 			    foreign->n_fields,
 			    ha_alter_info->key_info_buffer,
-			    ha_alter_info->index_add_buffer,
-			    ha_alter_info->index_add_count)) {
+			    span<uint>(ha_alter_info->index_add_buffer,
+				       ha_alter_info->index_add_count))) {
 
 			/* Index cannot be dropped. */
 			trx->error_info = index;
diff --git a/storage/innobase/include/ha_prototypes.h b/storage/innobase/include/ha_prototypes.h
index f37dff44b2f..cd7f5355818 100644
--- a/storage/innobase/include/ha_prototypes.h
+++ b/storage/innobase/include/ha_prototypes.h
@@ -119,9 +119,6 @@ thd_is_replication_slave_thread(
 /*============================*/
 	THD*	thd);	/*!< in: thread handle */
 
-/** @return whether statement-based replication is active */
-extern "C" int thd_rpl_stmt_based(const THD* thd);
-
 /******************************************************************//**
 Returns true if the transaction this thread is processing has edited
 non-transactional tables. Used by the deadlock detector when deciding
diff --git a/storage/innobase/include/log0log.h b/storage/innobase/include/log0log.h
index 5c03db5c751..9015d78bf67 100644
--- a/storage/innobase/include/log0log.h
+++ b/storage/innobase/include/log0log.h
@@ -40,6 +40,10 @@ Created 12/9/1995 Heikki Tuuri
 #include "os0event.h"
 #include "os0file.h"
 
+#ifndef UINT32_MAX
+#define UINT32_MAX             (4294967295U)
+#endif
+
 /** Maximum number of srv_n_log_files, or innodb_log_files_in_group */
 #define SRV_N_LOG_FILES_MAX 100
 
@@ -489,6 +493,12 @@ MariaDB 10.2.18 and later will use the 10.3 format, but LOG_HEADER_SUBFORMAT
 					header */
 #define LOG_FILE_HDR_SIZE	(4 * OS_FILE_LOG_BLOCK_SIZE)
 
+/* As long as fil_io() is used to handle log io, log group max size is limited
+by (maximum page number) * (minimum page size). Page number type is uint32_t.
+Remove this limitation if page number is no longer used for log file io. */
+static const ulonglong log_group_max_size =
+	((ulonglong(UINT32_MAX) + 1) * UNIV_PAGE_SIZE_MIN - 1);
+
 typedef ib_mutex_t	LogSysMutex;
 typedef ib_mutex_t	FlushOrderMutex;
 
diff --git a/storage/innobase/include/log0log.ic b/storage/innobase/include/log0log.ic
index 41f987aee6b..7dfa7c0db68 100644
--- a/storage/innobase/include/log0log.ic
+++ b/storage/innobase/include/log0log.ic
@@ -185,7 +185,9 @@ log_block_convert_lsn_to_no(
 /*========================*/
 	lsn_t	lsn)	/*!< in: lsn of a byte within the block */
 {
-	return(((ulint) (lsn / OS_FILE_LOG_BLOCK_SIZE) & 0x3FFFFFFFUL) + 1);
+	return(((ulint) (lsn / OS_FILE_LOG_BLOCK_SIZE) &
+		DBUG_EVALUATE_IF("innodb_small_log_block_no_limit",
+			0xFUL, 0x3FFFFFFFUL)) + 1);
 }
 
 /************************************************************//**
diff --git a/storage/innobase/include/row0ins.h b/storage/innobase/include/row0ins.h
index 0906b516c35..82bb3c91171 100644
--- a/storage/innobase/include/row0ins.h
+++ b/storage/innobase/include/row0ins.h
@@ -198,10 +198,6 @@ struct ins_node_t{
 				entry_list and sys fields are stored here;
 				if this is NULL, entry list should be created
 				and buffers for sys fields in row allocated */
-	dict_index_t*   duplicate;
-				/* This is the first index that reported
-				DB_DUPLICATE_KEY.  Used in the case of REPLACE
-				or INSERT ... ON DUPLICATE UPDATE. */
 	ulint		magic_n;
 };
 
diff --git a/storage/innobase/include/span.h b/storage/innobase/include/span.h
new file mode 100644
index 00000000000..faeb41029b8
--- /dev/null
+++ b/storage/innobase/include/span.h
@@ -0,0 +1,145 @@
+/*****************************************************************************
+
+Copyright (c) 2019, MariaDB Corporation.
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; version 2 of the License.
+
+This program is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+*****************************************************************************/
+
+#pragma once
+
+#include <cstddef>
+#include <iterator>
+
+namespace st_ {
+
+template <class ElementType> class span {
+public:
+	typedef ElementType element_type;
+	typedef ElementType value_type;
+	typedef size_t index_type;
+	typedef ptrdiff_t difference_type;
+	typedef element_type* pointer;
+	typedef const element_type* const_pointer;
+	typedef element_type& reference;
+	typedef const element_type& const_reference;
+	typedef pointer iterator;
+	typedef const pointer const_iterator;
+	typedef std::reverse_iterator<iterator> reverse_iterator;
+	typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
+
+	span() : data_(NULL), size_(0) {}
+
+	span(pointer ptr, index_type count) : data_(ptr), size_(count) {}
+
+	span(pointer first, pointer last) : data_(first), size_(last - first) {}
+
+	template <size_t N> span(element_type (&arr)[N]) : data_(arr), size_(N)
+	{
+	}
+
+	template <class Container>
+	span(Container& cont) : data_(cont.begin()), size_(cont.size())
+	{
+	}
+
+	template <class Container>
+	span(const Container& cont) : data_(cont.begin()), size_(cont.size())
+	{
+	}
+
+	span(const span& other) : data_(other.data_), size_(other.size_) {}
+
+	~span(){};
+
+	span& operator=(const span& other)
+	{
+		data_ = other.data_;
+		size_ = other.size_;
+		return *this;
+	}
+
+	template <size_t Count> span<element_type> first() const
+	{
+		assert(!empty());
+		return span(data_, 1);
+	}
+	template <size_t Count> span<element_type> last() const
+	{
+		assert(!empty());
+		return span(data_ + size() - 1, 1);
+	}
+
+	span<element_type> first(index_type count) const
+	{
+		assert(!empty());
+		return span(data_, 1);
+	}
+	span<element_type> last(index_type count) const
+	{
+		assert(!empty());
+		return span(data_ + size() - 1, 1);
+	}
+	span<element_type> subspan(index_type offset, index_type count) const
+	{
+		assert(!empty());
+		assert(size() >= offset + count);
+		return span(data_ + offset, count);
+	}
+
+	index_type size() const { return size_; }
+	index_type size_bytes() const { return size_ * sizeof(ElementType); }
+	bool empty() const __attribute__((warn_unused_result))
+	{
+		return size_ == 0;
+	}
+
+	reference operator[](index_type idx) const
+	{
+		assert(size() > idx);
+		return data_[idx];
+	}
+	reference front() const
+	{
+		assert(!empty());
+		return data_[0];
+	}
+	reference back() const
+	{
+		assert(!empty());
+		return data_[size() - 1];
+	}
+	pointer data() const
+	{
+		assert(!empty());
+		return data_;
+	}
+
+	iterator begin() const { return data_; }
+	iterator end() const { return data_ + size_; }
+	reverse_iterator rbegin() const
+	{
+		return std::reverse_iterator<iterator>(std::advance(end(), -1));
+	}
+	reverse_iterator rend() const
+	{
+		return std::reverse_iterator<iterator>(
+		    std::advance(begin(), -1));
+	}
+
+private:
+	pointer data_;
+	index_type size_;
+};
+
+} // namespace st_
diff --git a/storage/innobase/log/log0log.cc b/storage/innobase/log/log0log.cc
index c9a94f953d7..0e794a865d1 100644
--- a/storage/innobase/log/log0log.cc
+++ b/storage/innobase/log/log0log.cc
@@ -753,11 +753,14 @@ loop:
 	the trailer fields of the log blocks */
 
 	for (i = 0; i < write_len / OS_FILE_LOG_BLOCK_SIZE; i++) {
+#ifdef UNIV_DEBUG
+		ulint hdr_no_2 = log_block_get_hdr_no(buf) + i;
+		DBUG_EXECUTE_IF("innodb_small_log_block_no_limit",
+				hdr_no_2 = ((hdr_no_2 - 1) & 0xFUL) + 1;);
+#endif
 		ut_ad(pad_len >= len
-		      || i * OS_FILE_LOG_BLOCK_SIZE >= len - pad_len
-		      || log_block_get_hdr_no(
-			      buf + i * OS_FILE_LOG_BLOCK_SIZE)
-			 == log_block_get_hdr_no(buf) + i);
+			|| i * OS_FILE_LOG_BLOCK_SIZE >= len - pad_len
+			|| log_block_get_hdr_no(buf + i * OS_FILE_LOG_BLOCK_SIZE) == hdr_no_2);
 		log_block_store_checksum(buf + i * OS_FILE_LOG_BLOCK_SIZE);
 	}
 
diff --git a/storage/innobase/que/que0que.cc b/storage/innobase/que/que0que.cc
index a3e1948da27..6e4bce86df8 100644
--- a/storage/innobase/que/que0que.cc
+++ b/storage/innobase/que/que0que.cc
@@ -684,11 +684,6 @@ que_thr_stop(
 		trx->lock.wait_thr = thr;
 		thr->state = QUE_THR_LOCK_WAIT;
 
-	} else if (trx->duplicates && trx->error_state == DB_DUPLICATE_KEY
-		   && thd_rpl_stmt_based(trx->mysql_thd)) {
-
-		return(FALSE);
-
 	} else if (trx->error_state != DB_SUCCESS
 		   && trx->error_state != DB_LOCK_WAIT) {
 
diff --git a/storage/innobase/row/row0ins.cc b/storage/innobase/row/row0ins.cc
index bd894d06541..e1749f9ea78 100644
--- a/storage/innobase/row/row0ins.cc
+++ b/storage/innobase/row/row0ins.cc
@@ -85,7 +85,6 @@ ins_node_create(
 	node->select = NULL;
 
 	node->trx_id = 0;
-	node->duplicate = NULL;
 
 	node->entry_sys_heap = mem_heap_create(128);
 
@@ -190,7 +189,6 @@ ins_node_set_new_row(
 	node->state = INS_NODE_SET_IX_LOCK;
 	node->index = NULL;
 	node->entry = NULL;
-	node->duplicate = NULL;
 
 	node->row = row;
 
@@ -2346,12 +2344,6 @@ row_ins_duplicate_error_in_clust(
 						  true,
 						  ULINT_UNDEFINED, &heap);
 
-			ulint lock_type =
-				trx->isolation_level <= TRX_ISO_READ_COMMITTED
-				|| (trx->mysql_thd
-				    && !thd_rpl_stmt_based(trx->mysql_thd))
-				? LOCK_REC_NOT_GAP : LOCK_ORDINARY;
-
 			/* We set a lock on the possible duplicate: this
 			is needed in logical logging of MySQL to make
 			sure that in roll-forward we get the same duplicate
@@ -2368,13 +2360,13 @@ row_ins_duplicate_error_in_clust(
 				INSERT ON DUPLICATE KEY UPDATE). */
 
 				err = row_ins_set_exclusive_rec_lock(
-					lock_type,
+					LOCK_REC_NOT_GAP,
 					btr_cur_get_block(cursor),
 					rec, cursor->index, offsets, thr);
 			} else {
 
 				err = row_ins_set_shared_rec_lock(
-					lock_type,
+					LOCK_REC_NOT_GAP,
 					btr_cur_get_block(cursor), rec,
 					cursor->index, offsets, thr);
 			}
@@ -2389,7 +2381,10 @@ row_ins_duplicate_error_in_clust(
 
 			if (row_ins_dupl_error_with_rec(
 				    rec, entry, cursor->index, offsets)) {
-				goto duplicate;
+duplicate:
+				trx->error_info = cursor->index;
+				err = DB_DUPLICATE_KEY;
+				goto func_exit;
 			}
 		}
 	}
@@ -2432,10 +2427,7 @@ row_ins_duplicate_error_in_clust(
 
 			if (row_ins_dupl_error_with_rec(
 				    rec, entry, cursor->index, offsets)) {
-duplicate:
-				trx->error_info = cursor->index;
-				err = DB_DUPLICATE_KEY;
-				goto func_exit;
+				goto duplicate;
 			}
 		}
 
@@ -3083,46 +3075,6 @@ row_ins_sec_index_entry_low(
 			&cursor, 0, __FILE__, __LINE__, &mtr);
 	}
 
-	if (!(flags & BTR_NO_LOCKING_FLAG)
-	    && dict_index_is_unique(index)
-	    && thr_get_trx(thr)->duplicates
-	    && thr_get_trx(thr)->isolation_level >= TRX_ISO_REPEATABLE_READ
-	    && thd_rpl_stmt_based(thr_get_trx(thr)->mysql_thd)) {
-
-		/* In statement-based replication, when replicating a
-		REPLACE statement or ON DUPLICATE KEY UPDATE clause, a
-		gap lock is taken on the position of the to-be-inserted record,
-		to avoid other concurrent transactions from inserting the same
-		record. */
-
-		dberr_t	err;
-		const rec_t* rec = page_rec_get_next_const(
-			btr_cur_get_rec(&cursor));
-
-		ut_ad(!page_rec_is_infimum(rec));
-
-		offsets = rec_get_offsets(rec, index, offsets, true,
-					  ULINT_UNDEFINED, &offsets_heap);
-
-		err = row_ins_set_exclusive_rec_lock(
-			LOCK_GAP, btr_cur_get_block(&cursor), rec,
-			index, offsets, thr);
-
-		switch (err) {
-		case DB_SUCCESS:
-		case DB_SUCCESS_LOCKED_REC:
-			if (thr_get_trx(thr)->error_state != DB_DUPLICATE_KEY) {
-				break;
-			}
-			/* Fall through (skip actual insert) after we have
-			successfully acquired the gap lock. */
-		default:
-			goto func_exit;
-		}
-	}
-
-	ut_ad(thr_get_trx(thr)->error_state == DB_SUCCESS);
-
 	if (dup_chk_only) {
 		goto func_exit;
 	}
@@ -3682,13 +3634,6 @@ row_ins(
 
 	DBUG_PRINT("row_ins", ("table: %s", node->table->name.m_name));
 
-	trx_t* trx = thr_get_trx(thr);
-
-	if (node->duplicate) {
-		ut_ad(thd_rpl_stmt_based(trx->mysql_thd));
-		trx->error_state = DB_DUPLICATE_KEY;
-	}
-
 	if (node->state == INS_NODE_ALLOC_ROW_ID) {
 
 		row_ins_alloc_row_id_step(node);
@@ -3714,91 +3659,7 @@ row_ins(
 		if (node->index->type != DICT_FTS) {
 			dberr_t err = row_ins_index_entry_step(node, thr);
 
-			switch (err) {
-			case DB_SUCCESS:
-				break;
-			case DB_NO_REFERENCED_ROW:
-				if (!dict_index_is_unique(node->index)) {
-					DBUG_RETURN(err);
-				}
-				/* fall through */
-			case DB_DUPLICATE_KEY:
-				ut_ad(dict_index_is_unique(node->index));
-
-				if (trx->isolation_level
-				    >= TRX_ISO_REPEATABLE_READ
-				    && trx->duplicates
-				    && !node->table->is_temporary()
-				    && thd_rpl_stmt_based(trx->mysql_thd)) {
-
-					/* When we are in REPLACE statement or
-					INSERT ..  ON DUPLICATE UPDATE
-					statement, we process all the
-					unique secondary indexes, even after we
-					encounter a duplicate error. This is
-					done to take necessary gap locks in
-					secondary indexes to block concurrent
-					transactions from inserting the
-					searched records. */
-					if (err == DB_NO_REFERENCED_ROW
-					    && node->duplicate) {
-						/* A foreign key check on a
-						unique index may fail to
-						find the record.
-
-						Consider as a example
-						following:
-						create table child(a int not null
-						primary key, b int not null,
-						c int,
-						unique key (b),
-						foreign key (b) references
-						parent (id)) engine=innodb;
-
-						insert into child values
-						(1,1,2);
-
-						insert into child(a) values
-						(1) on duplicate key update
-						c = 3;
-
-						Now primary key value 1
-						naturally causes duplicate
-						key error that will be
-						stored on node->duplicate.
-						If there was no duplicate
-						key error, we should return
-						the actual no referenced
-						row error.
-
-						As value for
-						column b used in both unique
-						key and foreign key is not
-						provided, server uses 0 as a
-						search value. This is
-						naturally, not found leading
-						to DB_NO_REFERENCED_ROW.
-						But, we should update the
-						row with primay key value 1
-						anyway.
-
-						Return the
-						original  DB_DUPLICATE_KEY
-						error after
-						placing all gaplocks. */
-						err = DB_DUPLICATE_KEY;
-						break;
-					} else if (!node->duplicate) {
-						/* Save 1st dup error. Ignore
-						subsequent dup errors. */
-						node->duplicate = node->index;
-						trx->error_state
-							= DB_DUPLICATE_KEY;
-					}
-					break;
-				}
-				// fall through
-			default:
+			if (err != DB_SUCCESS) {
 				DBUG_RETURN(err);
 			}
 		}
@@ -3815,31 +3676,13 @@ row_ins(
 			node->index = dict_table_get_next_index(node->index);
 			node->entry = UT_LIST_GET_NEXT(tuple_list, node->entry);
 		}
-
-		/* After encountering a duplicate key error, we process
-		remaining indexes just to place gap locks and no actual
-		insertion will take place.  These gap locks are needed
-		only for unique indexes.  So skipping non-unique indexes. */
-		if (node->duplicate) {
-			ut_ad(thd_rpl_stmt_based(trx->mysql_thd));
-			while (node->index
-			       && !dict_index_is_unique(node->index)) {
-
-				node->index = dict_table_get_next_index(
-					node->index);
-				node->entry = UT_LIST_GET_NEXT(tuple_list,
-							       node->entry);
-			}
-			trx->error_state = DB_DUPLICATE_KEY;
-		}
 	}
 
 	ut_ad(node->entry == NULL);
 
-	trx->error_info = node->duplicate;
 	node->state = INS_NODE_ALLOC_ROW_ID;
 
-	DBUG_RETURN(node->duplicate ? DB_DUPLICATE_KEY : DB_SUCCESS);
+	DBUG_RETURN(DB_SUCCESS);
 }
 
 /***********************************************************//**
diff --git a/storage/innobase/row/row0mysql.cc b/storage/innobase/row/row0mysql.cc
index c834fba9b13..6d70cbfa0fa 100644
--- a/storage/innobase/row/row0mysql.cc
+++ b/storage/innobase/row/row0mysql.cc
@@ -1480,7 +1480,6 @@ error_exit:
 			goto run_again;
 		}
 
-		node->duplicate = NULL;
 		trx->op_info = "";
 
 		if (blob_heap != NULL) {
@@ -1490,8 +1489,6 @@ error_exit:
 		return(err);
 	}
 
-	node->duplicate = NULL;
-
 	if (dict_table_has_fts_index(table)) {
 		doc_id_t	doc_id;
 
diff --git a/storage/innobase/srv/srv0start.cc b/storage/innobase/srv/srv0start.cc
index 5783bb9ae66..2be9e7ebd17 100644
--- a/storage/innobase/srv/srv0start.cc
+++ b/storage/innobase/srv/srv0start.cc
@@ -1761,7 +1761,7 @@ dberr_t srv_start(bool create_new_db)
 		ut_a(fil_validate());
 		ut_a(log_space);
 
-		ut_a(srv_log_file_size <= 512ULL << 30);
+		ut_a(srv_log_file_size <= log_group_max_size);
 
 		const ulint size = 1 + ulint((srv_log_file_size - 1)
 					     >> srv_page_size_shift);
diff --git a/storage/maria/maria_chk.c b/storage/maria/maria_chk.c
index aa2ad1d4618..54f7c21539b 100644
--- a/storage/maria/maria_chk.c
+++ b/storage/maria/maria_chk.c
@@ -1006,6 +1006,7 @@ static int maria_chk(HA_CHECK *param, char *filename)
   int error,lock_type,recreate;
   uint warning_printed_by_chk_status;
   my_bool rep_quick= MY_TEST(param->testflag & (T_QUICK | T_FORCE_UNIQUENESS));
+  my_bool born_transactional;
   MARIA_HA *info;
   File datafile;
   char llbuff[22],llbuff2[22];
@@ -1448,6 +1449,7 @@ static int maria_chk(HA_CHECK *param, char *filename)
   maria_lock_database(info, F_UNLCK);
 
 end2:
+  born_transactional= share->base.born_transactional;
   if (maria_close(info))
   {
     _ma_check_print_error(param, default_close_errmsg, my_errno, filename);
@@ -1463,7 +1465,7 @@ end2:
                                       MYF(MY_REDEL_MAKE_BACKUP) : MYF(0)));
   }
   if (opt_transaction_logging &&
-      share->base.born_transactional && !error &&
+      born_transactional && !error &&
       (param->testflag & (T_REP_ANY | T_SORT_RECORDS | T_SORT_INDEX |
                           T_ZEROFILL)))
     error= write_log_record(param);
diff --git a/storage/mroonga/vendor/groonga/lib/ts.c b/storage/mroonga/vendor/groonga/lib/ts.c
index 68e363a27d7..909f4864786 100644
--- a/storage/mroonga/vendor/groonga/lib/ts.c
+++ b/storage/mroonga/vendor/groonga/lib/ts.c
@@ -683,7 +683,7 @@ static grn_rc
 grn_ts_select_output(grn_ctx *ctx, grn_obj *table, grn_ts_str str,
                      const grn_ts_record *in, size_t n_in, size_t n_hits)
 {
-  grn_ts_writer *writer;
+  grn_ts_writer *writer= 0;
   grn_rc rc = grn_ts_writer_open(ctx, table, str, &writer);
   if (rc != GRN_SUCCESS) {
     return rc;
diff --git a/storage/mroonga/vendor/groonga/lib/ts/ts_expr_node.c b/storage/mroonga/vendor/groonga/lib/ts/ts_expr_node.c
index ddd69714b1e..4ae900034bb 100644
--- a/storage/mroonga/vendor/groonga/lib/ts/ts_expr_node.c
+++ b/storage/mroonga/vendor/groonga/lib/ts/ts_expr_node.c
@@ -5173,7 +5173,7 @@ grn_ts_expr_node_deref(grn_ctx *ctx, grn_ts_expr_node **node_ptr)
 {
   grn_ts_expr_node *node = *node_ptr, **in_ptr = NULL;
   while ((node->data_kind & ~GRN_TS_VECTOR_FLAG) == GRN_TS_REF) {
-    grn_ts_expr_node *new_node;
+    grn_ts_expr_node *new_node= 0;
     grn_rc rc = grn_ts_expr_node_deref_once(ctx, node, &new_node);
     if (rc != GRN_SUCCESS) {
       if (in_ptr) {
diff --git a/storage/rocksdb/ha_rocksdb.cc b/storage/rocksdb/ha_rocksdb.cc
index 7eb53dd878c..8ef8c349e9f 100644
--- a/storage/rocksdb/ha_rocksdb.cc
+++ b/storage/rocksdb/ha_rocksdb.cc
@@ -14320,6 +14320,8 @@ static int rocksdb_validate_update_cf_options(
   // then there's no point to proceed.
   if (!Rdb_cf_options::parse_cf_options(str, &option_map)) {
     my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), "rocksdb_update_cf_options", str);
+    // Free what we've copied with my_strdup above.
+    my_free((void*)(*(const char **)save));
     return HA_EXIT_FAILURE;
   }
   // Loop through option_map and create missing column families
diff --git a/storage/rocksdb/mysql-test/rocksdb/include/group_min_max.inc b/storage/rocksdb/mysql-test/rocksdb/include/group_min_max.inc
index 79ac367a73b..6c3e29537b1 100644
--- a/storage/rocksdb/mysql-test/rocksdb/include/group_min_max.inc
+++ b/storage/rocksdb/mysql-test/rocksdb/include/group_min_max.inc
@@ -266,6 +266,17 @@ select a1,  max(c)           from t2 where a1 in ('a','b','d') group by a1,a2,b;
 
 # B) Equalities only over the non-group 'B' attributes
 # plans
+--echo #
+--echo # MariaDB: we dont have the following patch:
+--echo #
+--echo #  commit 60a92a79a3b7fde3c6efe91799e344b977c8e5c3
+--echo #  Author: Manuel Ung <mung@fb.com>
+--echo #  Date:   Thu Apr 19 23:06:27 2018 -0700
+--echo #
+--echo #   Enhance group-by loose index scan
+--echo #
+--echo #  So the following results are not very meaningful, but are still kept here
+
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
@@ -730,9 +741,9 @@ explain extended select a1,a2,count(a2) from t1 where (a1 > 'a') group by a1,a2,
 explain extended select sum(ord(a1)) from t1 where (a1 > 'a') group by a1,a2,b;
 
 # test multi_range_groupby flag
-set optimizer_switch = 'multi_range_groupby=off';
+#MariaDB: no support: set optimizer_switch = 'multi_range_groupby=off';
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
-set optimizer_switch = 'default';
+#set optimizer_switch = 'default';
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 
 
@@ -1361,41 +1372,41 @@ drop table t1;
 eval CREATE TABLE t (a INT, b INT, KEY(a,b)) engine=$engine;
 INSERT INTO t VALUES (1,1), (2,2), (3,3), (4,4), (1,0), (3,2), (4,5);
 ANALYZE TABLE t;
-let $DEFAULT_TRACE_MEM_SIZE=1048576; # 1MB
-eval set optimizer_trace_max_mem_size=$DEFAULT_TRACE_MEM_SIZE;
-set @@session.optimizer_trace='enabled=on';
-set end_markers_in_json=on;
+# MariaDB: 10.2 doesn't have trace, yet: let $DEFAULT_TRACE_MEM_SIZE=1048576; # 1MB
+# eval set optimizer_trace_max_mem_size=$DEFAULT_TRACE_MEM_SIZE;
+# set @@session.optimizer_trace='enabled=on';
+# set end_markers_in_json=on;
 
 ANALYZE TABLE t;
 
 SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 EXPLAIN SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 EXPLAIN SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
-SET optimizer_trace_max_mem_size=DEFAULT;
-SET optimizer_trace=DEFAULT;
-SET end_markers_in_json=DEFAULT;
+#SET optimizer_trace_max_mem_size=DEFAULT;
+#SET optimizer_trace=DEFAULT;
+#SET end_markers_in_json=DEFAULT;
 
 DROP TABLE t;
 
diff --git a/storage/rocksdb/mysql-test/rocksdb/r/group_min_max.result b/storage/rocksdb/mysql-test/rocksdb/r/group_min_max.result
index 7fede0ac603..a1031f518e0 100644
--- a/storage/rocksdb/mysql-test/rocksdb/r/group_min_max.result
+++ b/storage/rocksdb/mysql-test/rocksdb/r/group_min_max.result
@@ -1,4 +1,5 @@
-set global debug="+d,force_group_by";
+set @debug_tmp= @@debug_dbug;
+set global debug_dbug="+d,force_group_by";
 drop table if exists t1;
 create table t1 (
 a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(248) default ' '
@@ -134,34 +135,34 @@ Table	Op	Msg_type	Msg_text
 test.t3	analyze	status	OK
 explain select a1, min(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, max(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	65	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	65	NULL	63	Using index for group-by
 explain select a1, min(a2), max(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, a2, b, min(c), max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t2 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	#	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	#	NULL	#	Using index for group-by
 explain select min(a2), a1, max(a2), min(a2), a1 from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, b, min(c), a1, max(c), b, a2, max(c), max(c) from t1 group by a1, a2, b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select min(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a2, min(c), max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 select a1, min(a2) from t1 group by a1;
 a1	min(a2)
 a	a
@@ -288,37 +289,37 @@ b	i421	l421
 b	m422	p422
 explain select a1,a2,b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	502	Using where; Using index for group-by
 explain select a1, max(c)            from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	2004	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1004	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	2004	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1004	Using where; Using index for group-by
 explain select a1,min(c),max(c)      from t1 where a1 >= 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,  max(c)           from t1 where a1 in ('a','b','d') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
@@ -668,99 +669,109 @@ d	d411
 d	h412
 d	l421
 d	p422
+#
+# MariaDB: we dont have the following patch:
+#
+#  commit 60a92a79a3b7fde3c6efe91799e344b977c8e5c3
+#  Author: Manuel Ung <mung@fb.com>
+#  Date:   Thu Apr 19 23:06:27 2018 -0700
+#
+#   Enhance group-by loose index scan
+#
+#  So the following results are not very meaningful, but are still kept here
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,       max(c) from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2, max(c)         from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,       max(c) from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2, max(c)         from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	range	NULL	idx_t3_1	6	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	range	NULL	idx_t3_1	6	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
 a	a	b	h112	e112
@@ -769,22 +780,22 @@ c	a	b	h312	e312
 d	a	b	h412	e412
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
-d	b	b	p422	e412
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
+d	a	b	p422	e412
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
-d	a	b	h412	a411
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
+d	a	a	h412	a411
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	a111
-b	b	b	p222	a211
-c	b	b	p322	a311
-d	b	b	p422	a411
+a	a	a	p122	a111
+b	a	a	p222	a211
+c	a	a	p322	a311
+d	a	a	p422	a411
 select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -815,14 +826,14 @@ d	a	b	h412
 d	b	b	p422
 select a1,a2,b,       max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	max(c)
-a	a	b	h112
-a	b	b	p122
-b	a	b	h212
-b	b	b	p222
-c	a	b	h312
-c	b	b	p322
-d	a	b	h412
-d	b	b	p422
+a	a	a	h112
+a	b	a	p122
+b	a	a	h212
+b	b	a	p222
+c	a	a	h312
+c	b	a	p322
+d	a	a	h412
+d	b	a	p422
 select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
 a1	a2	b	min(c)	max(c)
 a	a	b	e112	h112
@@ -835,14 +846,14 @@ d	a	b	e412	h412
 d	b	b	m422	p422
 select a1,a2,b,min(c),max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	min(c)	max(c)
-a	a	b	a111	h112
-a	b	b	i121	p122
-b	a	b	a211	h212
-b	b	b	i221	p222
-c	a	b	a311	h312
-c	b	b	i321	p322
-d	a	b	a411	h412
-d	b	b	i421	p422
+a	a	a	a111	h112
+a	b	a	i121	p122
+b	a	a	a211	h212
+b	b	a	i221	p222
+c	a	a	a311	h312
+c	b	a	i321	p322
+d	a	a	a411	h412
+d	b	a	i421	p422
 select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
 a1	a2	max(c)
 a	a	h112
@@ -872,17 +883,18 @@ d	a	b	h412	e412
 e	a	b	NULL	NULL
 select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
-d	b	b	p422	e412
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
+d	a	b	p422	e412
+e	a	b	NULL	NULL
 select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
-d	a	b	h412	a411
-e	a	b	NULL	NULL
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
+d	a	a	h412	a411
+e	a	a	NULL	NULL
 select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -896,6 +908,7 @@ a	p122	e112
 b	p222	e212
 c	p322	e312
 d	p422	e412
+e	NULL	NULL
 select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	max(c)	min(c)
 a	h112	a111
@@ -916,15 +929,15 @@ d	b	b	p422
 e	a	b	NULL
 select a1,a2,b,       max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	max(c)
-a	a	b	h112
-a	b	b	p122
-b	a	b	h212
-b	b	b	p222
-c	a	b	h312
-c	b	b	p322
-d	a	b	h412
-d	b	b	p422
-e	a	b	NULL
+a	a	a	h112
+a	b	a	p122
+b	a	a	h212
+b	b	a	p222
+c	a	a	h312
+c	b	a	p322
+d	a	a	h412
+d	b	a	p422
+e	a	a	NULL
 select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
 a1	a2	b	min(c)	max(c)
 a	a	b	e112	h112
@@ -938,15 +951,15 @@ d	b	b	m422	p422
 e	a	b	NULL	NULL
 select a1,a2,b,min(c),max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	min(c)	max(c)
-a	a	b	a111	h112
-a	b	b	i121	p122
-b	a	b	a211	h212
-b	b	b	i221	p222
-c	a	b	a311	h312
-c	b	b	i321	p322
-d	a	b	a411	h412
-d	b	b	i421	p422
-e	a	b	NULL	NULL
+a	a	a	a111	h112
+a	b	a	i121	p122
+b	a	a	a211	h212
+b	b	a	i221	p222
+c	a	a	a311	h312
+c	b	a	i321	p322
+d	a	a	a411	h412
+d	b	a	i421	p422
+e	a	a	NULL	NULL
 select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
 a1	a2	max(c)
 a	a	h112
@@ -976,14 +989,14 @@ b	a	b	h212	e212
 c	a	b	h312	e312
 select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
 select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
 select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -1001,37 +1014,41 @@ b	h212	a211
 c	h312	a311
 explain select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,max(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 a1	a2	b	min(c)
 a	a	NULL	a777
 c	a	NULL	c777
 select a1,a2,b,min(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 a1	a2	b	min(c)
+a	a	NULL	a777
+c	a	NULL	c777
 select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 a1	a2	b	max(c)
 a	a	NULL	a999
 c	a	NULL	c999
 select a1,a2,b,max(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 a1	a2	b	max(c)
+a	a	NULL	a999
+c	a	NULL	c999
 select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
 a1	a2	b	min(c)
 a	a	NULL	a777
@@ -1050,97 +1067,97 @@ a	a	NULL	a777	a999
 c	a	NULL	c777	c999
 explain select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c between 'b111' and 'g112') or (c between 'd000' and 'i110') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
 a1	a2	b	max(c)
 a	a	a	d111
@@ -1562,35 +1579,36 @@ explain select a1,a2,b,min(c),max(c) from t1
 where exists ( select * from t2 where t2.c = t1.c )
 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	Using where; Using index
-2	DEPENDENT SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
+1	PRIMARY	t1	index	NULL	idx_t1_1	163	NULL	1000	Using index
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	16	func	1	
+2	MATERIALIZED	t2	index	NULL	idx_t2_1	163	NULL	1000	Using index
 explain select a1,a2,b,min(c),max(c) from t1
 where exists ( select * from t2 where t2.c > 'b1' )
 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	PRIMARY	t1	index	NULL	idx_t1_1	163	NULL	1000	Using index
 2	SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where (ord(a1) > 97) and (ord(a2) + ord(a1) > 194) and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
@@ -1599,7 +1617,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
@@ -1695,31 +1713,31 @@ select a1,a2,b,min(c) from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') grou
 a1	a2	b	min(c)
 explain select a1,a2,b from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121' or c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121' or c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
@@ -1770,50 +1788,50 @@ select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1
 a1	a2	b
 explain select distinct a1,a2,b from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain extended select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_1	idx_t1_1	163	NULL	1001	99.90	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	501	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select distinct `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where ((`test`.`t1`.`c` = 'i121') and (`test`.`t1`.`b` = 'a') and (`test`.`t1`.`a2` >= 'b'))
+Note	1003	select distinct `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where `test`.`t1`.`b` = 'a' and `test`.`t1`.`c` = 'i121' and `test`.`t1`.`a2` >= 'b'
 explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct b from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using where; Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'e';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using index for group-by
 explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain extended select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t2	range	idx_t2_1	idx_t2_1	163	NULL	1001	99.90	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	501	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select distinct `test`.`t2`.`a1` AS `a1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where ((`test`.`t2`.`c` = 'i121') and (`test`.`t2`.`b` = 'a') and (`test`.`t2`.`a2` >= 'b'))
+Note	1003	select distinct `test`.`t2`.`a1` AS `a1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`b` = 'a' and `test`.`t2`.`c` = 'i121' and `test`.`t2`.`a2` >= 'b'
 explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct b from t2 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_1,idx_t2_2	idx_t2_2	146	NULL	1000	Using where; Using index
+1	SIMPLE	t2	index	NULL	idx_t2_2	146	NULL	1000	Using where; Using index
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'e';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	126	Using where; Using index for group-by
 select distinct a1,a2,b from t1;
 a1	a2	b
 a	a	a
@@ -1942,40 +1960,40 @@ c	e
 d	e
 explain select distinct a1,a2,b from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by; Using temporary; Using filesort
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'e' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using index for group-by
 explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by; Using temporary; Using filesort
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	#	Using where; Using index for group-by
@@ -2064,23 +2082,23 @@ select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'e' group by a1;
 a1
 explain select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1	idx_t1_1	163	NULL	1001	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	501	Using where; Using index for group-by (scanning)
 explain extended select count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	100.00	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`b` = 'c') and (`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
+Note	1003	select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where `test`.`t1`.`b` = 'c' and `test`.`t1`.`a1` > 'a' and `test`.`t1`.`a2` > 'a'
 explain select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using where; Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 explain extended select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	100.00	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select (98 + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`)) AS `98 + count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
+Note	1003	select 98 + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `98 + count(distinct a1,a2,b)` from `test`.`t1` where `test`.`t1`.`a1` > 'a' and `test`.`t1`.`a2` > 'a'
 select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
 count(distinct a1,a2,b)
 4
@@ -2098,19 +2116,19 @@ select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
 104
 explain select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,min(c)),b from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,min(c)),b,max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,a2),b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(ord(min(b)),ord(max(b))),min(b),max(b) from t1 group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using index for group-by
 select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
 a1	a2	b	concat(min(c), max(c))
 a	a	a	a111d111
@@ -2179,85 +2197,83 @@ concat(ord(min(b)),ord(max(b)))	min(b)	max(b)
 9798	a	b
 explain select a1,a2,b,d,min(c),max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	
 explain select a1,a2,b,d from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	
 explain extended select a1,a2,min(b),max(b) from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`c` > 'a111' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`
 explain extended select a1,a2,b,min(c),max(c) from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,min(`test`.`t1`.`c`) AS `min(c)`,max(`test`.`t1`.`c`) AS `max(c)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,min(`test`.`t1`.`c`) AS `min(c)`,max(`test`.`t1`.`c`) AS `max(c)` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`d` > 'xy2' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain extended select a1,a2,b,c from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b,c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`,`test`.`t1`.`c`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`d` > 'xy2' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`,`test`.`t1`.`c`
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b < 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b < 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b <= 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b <= 'b' and b >= 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain extended select a1,a2,b from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`c` > 'a111' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
 a1	a2	min(b)	c
 a	a	a	a111
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t2
 where (c > 'a000') and (c <= 'd999') and (c like '_8__') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	1000	Using where; Using index
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1, a2, b, c, min(d), max(d) from t1 group by a1,a2,b,c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1	idx_t1_1	163	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	
 explain select a1,a2,count(a2) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using index
 explain extended select a1,a2,count(a2) from t1 where (a1 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,count(`test`.`t1`.`a2`) AS `count(a2)` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,count(`test`.`t1`.`a2`) AS `count(a2)` from `test`.`t1` where `test`.`t1`.`a1` > 'a' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain extended select sum(ord(a1)) from t1 where (a1 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select sum(ord(`test`.`t1`.`a1`)) AS `sum(ord(a1))` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
-set optimizer_switch = 'multi_range_groupby=off';
+Note	1003	select sum(ord(`test`.`t1`.`a1`)) AS `sum(ord(a1))` from `test`.`t1` where `test`.`t1`.`a1` > 'a' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
-set optimizer_switch = 'default';
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select distinct(a1) from t1 where ord(a2) = 98;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_0	65	NULL	1000	Using where
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 select distinct(a1) from t1 where ord(a2) = 98;
 a1
 a
@@ -2266,7 +2282,7 @@ c
 d
 explain select a1 from t1 where a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using where; Using index for group-by
 select a1 from t1 where a2 = 'b' group by a1;
 a1
 a
@@ -2275,7 +2291,7 @@ c
 d
 explain select distinct a1 from t1 where a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using where; Using index for group-by
 select distinct a1 from t1 where a2 = 'b';
 a1
 a
@@ -2385,7 +2401,7 @@ INSERT INTO t1 (a) VALUES
 ('SOUTH EAST'), ('SOUTH WEST'), ('WESTERN');
 EXPLAIN SELECT DISTINCT a,a FROM t1 ORDER BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	PRIMARY	PRIMARY	66	NULL	1001	Using index for group-by
+1	SIMPLE	t1	index	NULL	PRIMARY	66	NULL	1000	Using index
 SELECT DISTINCT a,a FROM t1 ORDER BY a;
 a	a
 	
@@ -2477,7 +2493,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 FLUSH STATUS;
 SELECT max(b), a FROM t1 GROUP BY a;
 max(b)	a
@@ -2489,15 +2505,17 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 FLUSH STATUS;
 CREATE TABLE t2 engine=RocksDB SELECT max(b), a FROM t1 GROUP BY a;
 SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 SELECT * FROM (SELECT max(b), a FROM t1 GROUP BY a) b;
 max(b)	a
@@ -2509,6 +2527,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 (SELECT max(b), a FROM t1 GROUP BY a) UNION 
 (SELECT max(b), a FROM t1 GROUP BY a);
@@ -2521,50 +2540,52 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	16
 Handler_read_next	0
+Handler_read_retry	0
 EXPLAIN (SELECT max(b), a FROM t1 GROUP BY a) UNION 
 (SELECT max(b), a FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	a	a	5	NULL	501	Using index for group-by
-2	UNION	t1	range	a	a	5	NULL	501	Using index for group-by
-NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	Using temporary
+1	PRIMARY	t1	range	NULL	a	5	NULL	251	Using index for group-by
+2	UNION	t1	range	NULL	a	5	NULL	251	Using index for group-by
+NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 EXPLAIN SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
 FROM t1 AS t1_outer;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE EXISTS 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+2	SUBQUERY	t1	index	NULL	a	10	NULL	1000	Using index
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using where; Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	251	
+1	PRIMARY	t1_outer	ref	a	a	5	<subquery2>.max(b)	4	Using index
+2	MATERIALIZED	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 
 a > (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	range	a	a	5	NULL	501	Using index for group-by
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer	range	NULL	a	5	NULL	251	Using index for group-by
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2 
 ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) 
 AND t1_outer1.b = t1_outer2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using where; Using index
-1	PRIMARY	t1_outer1	ref	a	a	10	const,test.t1_outer2.b	1	Using where; Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer1	ref	a	a	5	const	4	Using where; Using index
+1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using where; Using index; Using join buffer (flat, BNL join)
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
 FROM t1 AS t1_outer) x2 FROM t1 AS t1_outer2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using index
 2	SUBQUERY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-3	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+3	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 CREATE TABLE t3 LIKE t1;
 FLUSH STATUS;
 INSERT INTO t3 SELECT a,MAX(b) FROM t1 GROUP BY a;
@@ -2572,6 +2593,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 DELETE FROM t3;
 FLUSH STATUS;
 INSERT INTO t3 SELECT 1, (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) 
@@ -2580,12 +2602,14 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 DELETE FROM t3 WHERE (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) > 10000;
 SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 DELETE FROM t3 WHERE (SELECT (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) x 
 FROM t1) > 10000;
@@ -2594,6 +2618,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	1
+Handler_read_retry	0
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a int, INDEX idx(a)) engine=RocksDB;
 INSERT INTO t1 VALUES
@@ -2604,7 +2629,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT DISTINCT(a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx	idx	5	NULL	1001	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx	5	NULL	501	Using index for group-by
 SELECT DISTINCT(a) FROM t1;
 a
 1
@@ -2612,7 +2637,7 @@ a
 4
 EXPLAIN SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx	idx	5	NULL	1001	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx	5	NULL	501	Using index for group-by
 SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
 a
 1
@@ -2640,7 +2665,7 @@ CREATE INDEX break_it ON t1 (a, b);
 EXPLAIN
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	break_it	break_it	10	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	break_it	10	NULL	251	Using index for group-by
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
 a	MIN(b)	MAX(b)
 1	1	3
@@ -2650,7 +2675,7 @@ a	MIN(b)	MAX(b)
 EXPLAIN
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	break_it	break_it	10	NULL	501	Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t1	range	NULL	break_it	10	NULL	251	Using index for group-by; Using temporary; Using filesort
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
 a	MIN(b)	MAX(b)
 4	1	3
@@ -2660,7 +2685,7 @@ a	MIN(b)	MAX(b)
 EXPLAIN
 SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	break_it	break_it	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	break_it	10	NULL	1000	Using index
 SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
 a	MIN(b)	MAX(b)	AVG(b)
 4	1	3	2.0000
@@ -2743,9 +2768,9 @@ a	b
 3	13
 explain extended select sql_buffer_result a, max(b)+1 from t1 where a = 0 group by a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	PRIMARY,index	PRIMARY	4	NULL	1	100.00	Using where; Using index for group-by; Using temporary
+1	SIMPLE	t1	ref	PRIMARY,index	PRIMARY	4	const	15	100.00	Using index; Using temporary
 Warnings:
-Note	1003	/* select#1 */ select sql_buffer_result `test`.`t1`.`a` AS `a`,(max(`test`.`t1`.`b`) + 1) AS `max(b)+1` from `test`.`t1` where (`test`.`t1`.`a` = 0) group by `test`.`t1`.`a`
+Note	1003	select sql_buffer_result `test`.`t1`.`a` AS `a`,max(`test`.`t1`.`b`) + 1 AS `max(b)+1` from `test`.`t1` where `test`.`t1`.`a` = 0 group by `test`.`t1`.`a`
 drop table t1;
 CREATE TABLE t1 (a int, b int, c int, d int,
 KEY foo (c,d,a,b), KEY bar (c,a,b,d)) engine=RocksDB;
@@ -2758,7 +2783,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT DISTINCT c FROM t1 WHERE d=4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	foo,bar	foo	10	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	foo	10	NULL	63	Using where; Using index for group-by
 SELECT DISTINCT c FROM t1 WHERE d=4;
 c
 1
@@ -2780,7 +2805,7 @@ test.t	analyze	status	OK
 EXPLAIN
 SELECT a, MIN(b) FROM t WHERE b <> 0 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MIN(b) FROM t WHERE b <> 0 GROUP BY a;
 a	MIN(b)
@@ -2790,7 +2815,7 @@ a	MIN(b)
 EXPLAIN
 SELECT a, MAX(b) FROM t WHERE b <> 1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MAX(b) FROM t WHERE b <> 1 GROUP BY a;
 a	MAX(b)
@@ -2801,7 +2826,7 @@ INSERT INTO t SELECT a, 2 FROM t;
 EXPLAIN
 SELECT a, MAX(b) FROM t WHERE b > 0 AND b < 2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MAX(b) FROM t WHERE b > 0 AND b < 2 GROUP BY a;
 a	MAX(b)
@@ -2915,7 +2940,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -2990,7 +3015,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -3072,7 +3097,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -3119,45 +3144,45 @@ Table	Op	Msg_type	Msg_text
 test.t2	analyze	status	OK
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a) FROM t1;
 COUNT(DISTINCT a)
 2
 EXPLAIN SELECT COUNT(DISTINCT a,b) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT a,b) FROM t1;
 COUNT(DISTINCT a,b)
 16
 EXPLAIN SELECT COUNT(DISTINCT b,a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT b,a) FROM t1;
 COUNT(DISTINCT b,a)
 16
 EXPLAIN SELECT COUNT(DISTINCT b) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index
 SELECT COUNT(DISTINCT b) FROM t1;
 COUNT(DISTINCT b)
 8
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
 COUNT(DISTINCT a)
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
 COUNT(DISTINCT b)
 8
 8
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index; Using filesort
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index; Using filesort
 SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
 COUNT(DISTINCT a)
 2
@@ -3170,7 +3195,7 @@ COUNT(DISTINCT a)
 2
 EXPLAIN SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index
 SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
 COUNT(DISTINCT a)
 2
@@ -3188,76 +3213,76 @@ COUNT(DISTINCT a)
 2
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
 COUNT(DISTINCT a)
 2
 EXPLAIN SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
 1
 1
 EXPLAIN SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
 1
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1_1	index	a	a	10	NULL	1000	Using index; Using temporary; Using filesort
-1	SIMPLE	t1_2	index	NULL	a	10	NULL	1000	Using index; Using join buffer (Block Nested Loop)
+1	SIMPLE	t1_1	index	NULL	a	10	NULL	1000	Using index; Using temporary; Using filesort
+1	SIMPLE	t1_2	index	NULL	a	10	NULL	1000	Using index; Using join buffer (flat, BNL join)
 SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
 COUNT(DISTINCT t1_1.a)
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT a), 12 FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a), 12 FROM t1;
 COUNT(DISTINCT a)	12
 2	12
 EXPLAIN SELECT COUNT(DISTINCT a, b, c) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT a, b, c) FROM t2;
 COUNT(DISTINCT a, b, c)
 16
 EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	5	NULL	251	Using index for group-by
+1	SIMPLE	t2	range	NULL	a	5	NULL	126	Using index for group-by
 SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
 COUNT(DISTINCT a)	SUM(DISTINCT a)	AVG(DISTINCT a)
 2	3	1.5000
 EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
 COUNT(DISTINCT a)	SUM(DISTINCT a)	AVG(DISTINCT f)
 2	3	1.0000
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, a)
 16	16
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, f)
 16	8
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, d)
 16	8
 EXPLAIN SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
 a	c	COUNT(DISTINCT c, a, b)
 1	1	1
@@ -3279,7 +3304,7 @@ a	c	COUNT(DISTINCT c, a, b)
 EXPLAIN SELECT COUNT(DISTINCT c, a, b) FROM t2
 WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using where; Using index for group-by (scanning)
+1	SIMPLE	t2	range	a	a	15	NULL	501	Using where; Using index for group-by
 SELECT COUNT(DISTINCT c, a, b) FROM t2
 WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
 COUNT(DISTINCT c, a, b)
@@ -3292,28 +3317,28 @@ GROUP BY b;
 COUNT(DISTINCT b)	SUM(DISTINCT b)
 EXPLAIN SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 a	COUNT(DISTINCT b)	SUM(DISTINCT b)
 1	8	36
 2	8	36
 EXPLAIN SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 COUNT(DISTINCT b)	SUM(DISTINCT b)
 8	36
 8	36
 EXPLAIN SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	1000	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	Using where
 SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
 COUNT(DISTINCT a, b)
 0
 EXPLAIN SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
 WHERE b = 13 AND c = 42 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	a	15	NULL	126	Using where; Using index for group-by
 SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
 WHERE b = 13 AND c = 42 GROUP BY a;
 a	COUNT(DISTINCT a)	SUM(DISTINCT a)
@@ -3327,14 +3352,14 @@ COUNT(DISTINCT a, b)	SUM(DISTINCT a)
 0	NULL
 EXPLAIN SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	a	a	15	NULL	1000	Using index
+1	SIMPLE	t2	index	NULL	a	15	NULL	1000	Using index
 SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
 SUM(DISTINCT a)	MAX(b)
 1	8
 2	8
 EXPLAIN SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 42 * (a + c + COUNT(DISTINCT c, a, b))
 126
@@ -3355,7 +3380,7 @@ SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 168
 EXPLAIN SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	a	a	15	NULL	1000	Using index
+1	SIMPLE	t2	index	NULL	a	15	NULL	1000	Using index
 SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;
 (SUM(DISTINCT a) + MAX(b))
 9
@@ -3383,7 +3408,7 @@ f1	COUNT(DISTINCT f2)
 3	4
 explain SELECT f1, COUNT(DISTINCT f2) FROM t1 GROUP BY f1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	PRIMARY	PRIMARY	5	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	PRIMARY	5	NULL	1000	Using index
 drop table t1;
 # End of test#50539.
 #
@@ -3395,9 +3420,6 @@ INSERT INTO t VALUES (1,1), (2,2), (3,3), (4,4), (1,0), (3,2), (4,5);
 ANALYZE TABLE t;
 Table	Op	Msg_type	Msg_text
 test.t	analyze	status	OK
-set optimizer_trace_max_mem_size=1048576;
-set @@session.optimizer_trace='enabled=on';
-set end_markers_in_json=on;
 ANALYZE TABLE t;
 Table	Op	Msg_type	Msg_text
 test.t	analyze	status	OK
@@ -3409,11 +3431,7 @@ a	SUM(DISTINCT a)	MIN(b)
 4	4	4
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 a	SUM(DISTINCT a)	MAX(b)
 1	1	1
@@ -3422,11 +3440,7 @@ a	SUM(DISTINCT a)	MAX(b)
 4	4	5
 EXPLAIN SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 a	MAX(b)
 1	1
@@ -3435,21 +3449,13 @@ a	MAX(b)
 4	5
 EXPLAIN SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 SUM(DISTINCT a)	MIN(b)	MAX(b)
 10	0	5
 EXPLAIN SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 a	SUM(DISTINCT a)	MIN(b)	MAX(b)
 1	1	0	1
@@ -3458,14 +3464,7 @@ a	SUM(DISTINCT a)	MIN(b)	MAX(b)
 4	4	4	5
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
-SET optimizer_trace_max_mem_size=DEFAULT;
-SET optimizer_trace=DEFAULT;
-SET end_markers_in_json=DEFAULT;
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 DROP TABLE t;
 #
 # Bug#18109609: LOOSE INDEX SCAN IS NOT USED WHEN IT SHOULD
@@ -3484,7 +3483,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT MAX(c2), c1 FROM t1 WHERE c1 = 4 GROUP BY c1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c1	c1	5	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	ref	c1	c1	5	const	1000	Using index
 FLUSH STATUS;
 SELECT MAX(c2), c1 FROM t1 WHERE c1 = 4 GROUP BY c1;
 MAX(c2)	c1
@@ -3492,12 +3491,14 @@ MAX(c2)	c1
 SHOW SESSION STATUS LIKE 'Handler_read%';
 Variable_name	Value
 Handler_read_first	0
-Handler_read_key	3
-Handler_read_last	1
-Handler_read_next	0
+Handler_read_key	1
+Handler_read_last	0
+Handler_read_next	20
 Handler_read_prev	0
+Handler_read_retry	0
 Handler_read_rnd	0
+Handler_read_rnd_deleted	0
 Handler_read_rnd_next	0
 DROP TABLE t1;
 # End of test for Bug#18109609
-set global debug="-d,force_group_by";
+set global debug_dbug=@debug_tmp;
diff --git a/storage/rocksdb/mysql-test/rocksdb/r/kill.result b/storage/rocksdb/mysql-test/rocksdb/r/kill.result
new file mode 100644
index 00000000000..19614e1fd95
--- /dev/null
+++ b/storage/rocksdb/mysql-test/rocksdb/r/kill.result
@@ -0,0 +1,6 @@
+CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=RocksDB;
+LOCK TABLE t1 WRITE;
+SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+FLUSH TABLES;
+ERROR HY000: MyRocks supports only READ COMMITTED and REPEATABLE READ isolation levels. Please change from current isolation level SERIALIZABLE
+DROP TABLE t1;
diff --git a/storage/rocksdb/mysql-test/rocksdb/t/group_min_max.test b/storage/rocksdb/mysql-test/rocksdb/t/group_min_max.test
index a9c44a71edd..eb66bd0e972 100644
--- a/storage/rocksdb/mysql-test/rocksdb/t/group_min_max.test
+++ b/storage/rocksdb/mysql-test/rocksdb/t/group_min_max.test
@@ -1,8 +1,9 @@
 --source include/have_debug.inc
-set global debug="+d,force_group_by";
+set @debug_tmp= @@debug_dbug;
+set global debug_dbug="+d,force_group_by";
 
 let $engine=RocksDB;
 --source include/group_min_max.inc
 
-set global debug="-d,force_group_by";
+set global debug_dbug=@debug_tmp;
 
diff --git a/storage/rocksdb/mysql-test/rocksdb/t/kill.test b/storage/rocksdb/mysql-test/rocksdb/t/kill.test
new file mode 100644
index 00000000000..a2809d969d5
--- /dev/null
+++ b/storage/rocksdb/mysql-test/rocksdb/t/kill.test
@@ -0,0 +1,9 @@
+--source include/have_binlog_format_row.inc
+--source include/have_rocksdb.inc
+
+CREATE TABLE t1 (pk INT PRIMARY KEY) ENGINE=RocksDB;
+LOCK TABLE t1 WRITE;
+SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+--error ER_ISOLATION_MODE_NOT_SUPPORTED
+FLUSH TABLES;
+DROP TABLE t1;
diff --git a/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_concurrent_delete.inc b/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_concurrent_delete.inc
index 55f466a4d31..5336c77ee83 100644
--- a/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_concurrent_delete.inc
+++ b/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_concurrent_delete.inc
@@ -1,4 +1,7 @@
---source include/have_rocksdb.inc
+# MariaDB: including the below too many times causes really long argv list
+# in win_main()'s argument which blows up some limit on Windows.
+# Comment it out:
+#--source include/have_rocksdb.inc
 --source include/have_debug_sync.inc
 
 --source include/count_sessions.inc