IB: moved VTQ funcs to separate file

5 files changed, 467 insertions, 372 deletions

diff --git a/storage/innobase/CMakeLists.txt b/storage/innobase/CMakeLists.txt
index dfcd348690b..f694f4fa512 100644
--- a/storage/innobase/CMakeLists.txt
+++ b/storage/innobase/CMakeLists.txt
@@ -149,7 +149,8 @@ SET(INNOBASE_SOURCES
 	ut/ut0ut.cc
 	ut/ut0vec.cc
 	ut/ut0wqueue.cc
-	ut/ut0timer.cc)
+	ut/ut0timer.cc
+	vers/vers0vtq.cc)
 
 IF(WITH_INNODB)
   # Legacy option
diff --git a/storage/innobase/dict/dict0load.cc b/storage/innobase/dict/dict0load.cc
index fa73380fcad..85f1296234a 100644
--- a/storage/innobase/dict/dict0load.cc
+++ b/storage/innobase/dict/dict0load.cc
@@ -3797,4 +3797,3 @@ dict_table_open_on_index_id(
 	}
 	return table;
 }
-
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index e96d9c52909..aea14e9ca59 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -53,7 +53,6 @@ this program; if not, write to the Free Software Foundation, Inc.,
 // MySQL 5.7 Header */
 // #include <sql_thd_internal_api.h>
 #include <table_cache.h>
-#include <tztime.h>
 #include <my_check_opt.h>
 #include <my_bitmap.h>
 #include <mysql/service_thd_alloc.h>
@@ -121,6 +120,7 @@ this program; if not, write to the Free Software Foundation, Inc.,
 #include "trx0xa.h"
 #include "ut0mem.h"
 #include "row0ext.h"
+#include "vers0vtq.h"
 
 #define thd_get_trx_isolation(X) ((enum_tx_isolation)thd_tx_isolation(X))
 
@@ -1537,23 +1537,6 @@ innobase_fts_store_docid(
 }
 #endif
 
-bool
-vtq_query_trx_id(THD* thd, void *out, ulonglong in_trx_id, vtq_field_t field);
-
-bool
-vtq_query_commit_ts(THD* thd, void *out, const MYSQL_TIME &commit_ts, vtq_field_t field, bool backwards);
-
-bool
-vtq_trx_sees(
-	THD *thd,
-	bool &result,
-	ulonglong trx_id1,
-	ulonglong trx_id0,
-	ulonglong commit_id1,
-	uchar iso_level1,
-	ulonglong commit_id0);
-
-
 /*************************************************************//**
 Check for a valid value of innobase_commit_concurrency.
 @return 0 for valid innodb_commit_concurrency */
@@ -23182,355 +23165,3 @@ ib_push_frm_error(
 		break;
 	}
 }
-
-
-inline
-void
-innobase_vtq_result(THD* thd, vtq_record_t& q, void *out, vtq_field_t field)
-{
-	ut_ad(field == VTQ_ALL || out);
-
-	switch (field) {
-	case VTQ_ALL:
-		if (out) {
-			*reinterpret_cast<vtq_record_t *>(out) = q;
-		}
-		break;
-	case VTQ_TRX_ID:
-		*reinterpret_cast<trx_id_t *>(out) = q.trx_id;
-		break;
-	case VTQ_COMMIT_ID:
-		*reinterpret_cast<trx_id_t *>(out) = q.commit_id;
-		break;
-	case VTQ_BEGIN_TS: {
-		MYSQL_TIME* out_ts = reinterpret_cast<MYSQL_TIME *>(out);
-		thd_get_timezone(thd)->gmt_sec_to_TIME(out_ts, q.begin_ts.tv_sec);
-		out_ts->second_part = q.begin_ts.tv_usec;
-		break;
-	}
-	case VTQ_COMMIT_TS: {
-		MYSQL_TIME* out_ts = reinterpret_cast<MYSQL_TIME *>(out);
-		thd_get_timezone(thd)->gmt_sec_to_TIME(out_ts, q.commit_ts.tv_sec);
-		out_ts->second_part = q.commit_ts.tv_usec;
-		break;
-	}
-	case VTQ_ISO_LEVEL:
-		*reinterpret_cast<uint *>(out) = q.iso_level;
-		break;
-	default:
-		ut_error;
-	}
-}
-
-
-inline
-const char *
-vtq_query_t::cache_result(mem_heap_t* heap, const rec_t* rec)
-{
-	prev_query.tv_sec = 0;
-	return dict_process_sys_vtq(heap, rec, result);
-}
-
-UNIV_INTERN
-bool
-vtq_query_trx_id(THD* thd, void *out, ulonglong _in_trx_id, vtq_field_t field)
-{
-	trx_t*		trx;
-	dict_index_t*	index;
-	btr_pcur_t	pcur;
-	dtuple_t*	tuple;
-	dfield_t*	dfield;
-	trx_id_t	trx_id_net;
-	mtr_t		mtr;
-	mem_heap_t*	heap;
-	rec_t*		rec;
-	bool		found = false;
-
-	DBUG_ENTER("vtq_query_trx_id");
-
-	if (_in_trx_id == 0) {
-		DBUG_RETURN(false);
-	}
-
-	ut_ad(sizeof(_in_trx_id) == sizeof(trx_id_t));
-	trx_id_t	in_trx_id = static_cast<trx_id_t>(_in_trx_id);
-
-	trx = thd_to_trx(thd);
-	ut_a(trx);
-
-	vtq_record_t	&cached = trx->vtq_query.result;
-
-	if (cached.trx_id == in_trx_id) {
-		innobase_vtq_result(thd, cached, out, field);
-		DBUG_RETURN(true);
-	}
-
-	index = dict_table_get_first_index(dict_sys->sys_vtq);
-	heap = mem_heap_create(0);
-
-	ut_ad(index);
-	ut_ad(dict_index_is_clust(index));
-
-	mach_write_to_8(
-		reinterpret_cast<byte*>(&trx_id_net),
-		in_trx_id);
-
-	tuple = dtuple_create(heap, 1);
-	dfield = dtuple_get_nth_field(tuple, DICT_FLD__SYS_VTQ__TRX_ID);
-	dfield_set_data(dfield, &trx_id_net, 8);
-	dict_index_copy_types(tuple, index, 1);
-
-	mtr_start_trx(&mtr, trx);
-	btr_pcur_open_on_user_rec(index, tuple, PAGE_CUR_GE,
-			BTR_SEARCH_LEAF, &pcur, &mtr);
-
-	if (!btr_pcur_is_on_user_rec(&pcur))
-		goto not_found;
-
-	rec = btr_pcur_get_rec(&pcur);
-	{
-		const char *err = trx->vtq_query.cache_result(heap, rec);
-		if (err) {
-			fprintf(stderr, "InnoDB: vtq_query_trx_id: get VTQ field failed: %s\n", err);
-			ut_ad(false && "get VTQ field failed");
-			goto not_found;
-		}
-	}
-
-	if (cached.trx_id != in_trx_id)
-		goto not_found;
-
-	innobase_vtq_result(thd, cached, out, field);
-	found = true;
-
-not_found:
-	btr_pcur_close(&pcur);
-	mtr_commit(&mtr);
-	mem_heap_free(heap);
-
-	DBUG_RETURN(found);
-}
-
-static
-inline
-void rec_get_timeval(const rec_t* rec, ulint nfield, timeval& out)
-{
-	ulint		len;
-	const byte*	field;
-	field = rec_get_nth_field_old(
-		rec, nfield, &len);
-
-	ut_ad(len == sizeof(ullong));
-
-	out.tv_sec = mach_read_from_4(field);
-	out.tv_usec = mach_read_from_4(field + 4);
-}
-
-inline
-const char *
-vtq_query_t::cache_result(
-	mem_heap_t* heap,
-	const rec_t* rec,
-	const timeval& _ts_query,
-	bool _backwards)
-{
-	prev_query = _ts_query;
-	backwards = _backwards;
-	return dict_process_sys_vtq(heap, rec, result);
-}
-
-static
-inline
-bool
-operator== (const timeval &a, const timeval &b)
-{
-	return a.tv_sec == b.tv_sec && a.tv_usec == b.tv_usec;
-}
-
-static
-inline
-bool
-operator> (const timeval &a, const timeval &b)
-{
-	return a.tv_sec > b.tv_sec || (a.tv_sec == b.tv_sec && a.tv_usec > b.tv_usec);
-}
-
-static
-inline
-bool
-operator< (const timeval &a, const timeval &b)
-{
-	return b > a;
-}
-
-UNIV_INTERN
-bool
-vtq_query_commit_ts(THD* thd, void *out, const MYSQL_TIME &_commit_ts, vtq_field_t field, bool backwards)
-{
-	trx_t*		trx;
-	btr_pcur_t	pcur;
-	dtuple_t*	tuple;
-	page_cur_mode_t mode;
-	mtr_t		mtr;
-	mem_heap_t*	heap;
-	uint		err;
-	timeval		commit_ts;
-	timeval		rec_ts = { 0, 0 };
-	const rec_t	*rec, *clust_rec;
-	dict_index_t*	index = dict_sys->vtq_commit_ts_ind;
-	dict_index_t*	clust_index;
-	bool		found = false;
-
-	DBUG_ENTER("vtq_query_commit_ts");
-
-	mode = backwards ? PAGE_CUR_LE : PAGE_CUR_GE;
-
-	trx = thd_to_trx(thd);
-	ut_a(trx);
-
-	vtq_record_t &cached = trx->vtq_query.result;
-	timeval &prev_query = trx->vtq_query.prev_query;
-	bool prev_bwds = trx->vtq_query.backwards;
-
-	commit_ts.tv_usec = _commit_ts.second_part;
-	commit_ts.tv_sec = thd_get_timezone(thd)->TIME_to_gmt_sec(&_commit_ts, &err);
-	if (err) {
-		if (err == ER_WARN_DATA_OUT_OF_RANGE) {
-			if (_commit_ts.year <= TIMESTAMP_MIN_YEAR) {
-				commit_ts.tv_usec = 0;
-				commit_ts.tv_sec = 1;
-			} else {
-				ut_ad(_commit_ts.year >= TIMESTAMP_MAX_YEAR);
-				commit_ts.tv_usec = TIME_MAX_SECOND_PART;
-				commit_ts.tv_sec = MY_TIME_T_MAX;
-			}
-		} else {
-			DBUG_RETURN(false);
-		}
-	} else if (cached.commit_ts == commit_ts ||
-		(prev_query.tv_sec && prev_bwds == backwards && (
-			(!backwards && (commit_ts < prev_query) && commit_ts > cached.commit_ts) ||
-			(backwards && (commit_ts > prev_query) && commit_ts < cached.commit_ts))))
-	{
-		innobase_vtq_result(thd, cached, out, field);
-		DBUG_RETURN(true);
-	}
-
-	heap = mem_heap_create(0);
-
-	tuple = dtuple_create(heap, 1);
-	dict_index_copy_types(tuple, index, 1);
-	dtuple_get_nth_field(tuple, 0)->len = UNIV_SQL_NULL;
-	set_tuple_col_8(tuple, 0, commit_ts, heap);
-
-	mtr_start_trx(&mtr, trx);
-	btr_pcur_open_on_user_rec(index, tuple, mode,
-			BTR_SEARCH_LEAF, &pcur, &mtr);
-
-	if (btr_pcur_is_on_user_rec(&pcur)) {
-		rec = btr_pcur_get_rec(&pcur);
-		rec_get_timeval(rec, 0, rec_ts);
-
-		if (rec_ts.tv_sec == commit_ts.tv_sec
-		&& rec_ts.tv_usec == commit_ts.tv_usec)
-			goto found;
-	} else {
-		rec_ts = commit_ts;
-	}
-
-	if (mode == PAGE_CUR_GE) {
-		btr_pcur_move_to_prev_user_rec(&pcur, &mtr);
-	} else {
-		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
-	}
-
-	if (!btr_pcur_is_on_user_rec(&pcur))
-		goto not_found;
-
-	rec = btr_pcur_get_rec(&pcur);
-found:
-	clust_rec = row_get_clust_rec(BTR_SEARCH_LEAF, rec, index, &clust_index, &mtr);
-	if (!clust_rec) {
-		fprintf(stderr, "InnoDB: vtq_query_commit_ts: secondary index is out of sync\n");
-		ut_ad(false && "secondary index is out of sync");
-		goto not_found;
-	}
-
-	{
-		const char *err =
-			trx->vtq_query.cache_result(
-				heap,
-				clust_rec,
-				rec_ts,
-				backwards);
-		if (err) {
-			fprintf(stderr, "InnoDB: vtq_query_commit_ts: get VTQ field failed: %s\n", err);
-			ut_ad(false && "get VTQ field failed");
-			goto not_found;
-		}
-	}
-	innobase_vtq_result(thd, cached, out, field);
-	found = true;
-
-not_found:
-	btr_pcur_close(&pcur);
-	mtr_commit(&mtr);
-	mem_heap_free(heap);
-
-	DBUG_RETURN(found);
-}
-
-bool
-vtq_trx_sees(
-	THD *thd,
-	bool &result,
-	ulonglong trx_id1,
-	ulonglong trx_id0,
-	ulonglong commit_id1,
-	uchar iso_level1,
-	ulonglong commit_id0)
-{
-	DBUG_ENTER("vtq_trx_sees");
-
-	if (trx_id1 == trx_id0) {
-		result = false;
-		DBUG_RETURN(true);
-	}
-
-	if (trx_id1 == ULONGLONG_MAX || trx_id0 == 0) {
-		result = true;
-		DBUG_RETURN(true);
-	}
-
-	static const char* msg_cant_find = "InnoDB: vtq_trx_sees: can't find COMMIT_ID%c by TRX_ID: %llu\n";
-	if (!commit_id1) {
-		if (!vtq_query_trx_id(thd, NULL, trx_id1, VTQ_ALL)) {
-			fprintf(stderr, msg_cant_find, '1', trx_id1);
-			DBUG_RETURN(false);
-		}
-		trx_t* trx = thd_to_trx(thd);
-		ut_ad(trx);
-		commit_id1 = trx->vtq_query.result.commit_id;
-		iso_level1 = trx->vtq_query.result.iso_level;
-	}
-
-	if (!commit_id0) {
-		if (!vtq_query_trx_id(thd, &commit_id0, trx_id0, VTQ_COMMIT_ID)) {
-			fprintf(stderr, msg_cant_find, '0', trx_id0);
-			DBUG_RETURN(false);
-		}
-	}
-
-	// Trivial case: TX1 started after TX0 committed
-	if (trx_id1 > commit_id0
-		// Concurrent transactions: TX1 committed after TX0 and TX1 is read (un)committed
-		|| (commit_id1 > commit_id0 && iso_level1 < TRX_ISO_REPEATABLE_READ))
-	{
-		result = true;
-	} else {
-		// All other cases: TX1 does not see TX0
-		result = false;
-	}
-
-	DBUG_RETURN(true);
-}
diff --git a/storage/innobase/include/vers0vtq.h b/storage/innobase/include/vers0vtq.h
new file mode 100644
index 00000000000..2b486c25271
--- /dev/null
+++ b/storage/innobase/include/vers0vtq.h
@@ -0,0 +1,52 @@
+/* Copyright (c) 2017, 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  02110-1301, USA */
+
+/** Query VTQ by TRX_ID.
+@param[in]	thd	MySQL thread
+@param[out]	out	field value or whole record returned by query (selected by `field`)
+@param[in]	in_trx_id query parameter TRX_ID
+@param[in]	field	field to get in `out` or VTQ_ALL for whole record (vtq_record_t)
+@return	TRUE if record is found, FALSE otherwise */
+bool
+vtq_query_trx_id(THD* thd, void *out, ulonglong in_trx_id, vtq_field_t field);
+
+/** Query VTQ by COMMIT_TS.
+@param[in]	thd	MySQL thread
+@param[out]	out	field value or whole record returned by query (selected by `field`)
+@param[in]	commit_ts query parameter COMMIT_TS
+@param[in]	field	field to get in `out` or VTQ_ALL for whole record (vtq_record_t)
+@param[in]	backwards direction of VTQ search
+@return	TRUE if record is found, FALSE otherwise */
+bool
+vtq_query_commit_ts(THD* thd, void *out, const MYSQL_TIME &commit_ts, vtq_field_t field, bool backwards);
+
+/** Check if transaction TX1 sees transaction TX0.
+@param[in]	thd	MySQL thread
+@param[out]	result	true if TX1 sees TX0
+@param[in]	trx_id1	TX1 TRX_ID
+@param[in]	trx_id0	TX0 TRX_ID
+@param[in]	commit_id1 TX1 COMMIT_ID
+@param[in]	iso_level1 TX1 isolation level
+@param[in]	commit_id0 TX0 COMMIT_ID
+@return	FALSE if there is no trx_id1 in VTQ, otherwise TRUE */
+bool
+vtq_trx_sees(
+	THD *thd,
+	bool &result,
+	ulonglong trx_id1,
+	ulonglong trx_id0,
+	ulonglong commit_id1,
+	uchar iso_level1,
+	ulonglong commit_id0);
diff --git a/storage/innobase/vers/vers0vtq.cc b/storage/innobase/vers/vers0vtq.cc
new file mode 100644
index 00000000000..66ffc69829a
--- /dev/null
+++ b/storage/innobase/vers/vers0vtq.cc
@@ -0,0 +1,412 @@
+/* Copyright (c) 2017, 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  02110-1301, USA */
+
+#include <sql_class.h>
+#include <tztime.h>
+
+#include "btr0pcur.h"
+#include "dict0load.h"
+#include "ha_innodb.h"
+#include "row0ins.ic"
+#include "row0row.h"
+#include "trx0trx.h"
+#include "trx0types.h"
+#include "trx0vtq.h"
+
+
+/** Field or record selector.
+@param[in]	thd	MySQL thread
+@param[in]	q	VTQ record to get values from
+@param[out]	out	field value or whole record returned
+@param[in]	field	field to get in `out` or VTQ_ALL for whole record (vtq_record_t copied) */
+static
+inline
+void
+vtq_result(THD* thd, vtq_record_t& q, void *out, vtq_field_t field)
+{
+	ut_ad(field == VTQ_ALL || out);
+
+	switch (field) {
+	case VTQ_ALL:
+		if (out) {
+			*reinterpret_cast<vtq_record_t *>(out) = q;
+		}
+		break;
+	case VTQ_TRX_ID:
+		*reinterpret_cast<trx_id_t *>(out) = q.trx_id;
+		break;
+	case VTQ_COMMIT_ID:
+		*reinterpret_cast<trx_id_t *>(out) = q.commit_id;
+		break;
+	case VTQ_BEGIN_TS: {
+		MYSQL_TIME* out_ts = reinterpret_cast<MYSQL_TIME *>(out);
+		thd_get_timezone(thd)->gmt_sec_to_TIME(out_ts, q.begin_ts.tv_sec);
+		out_ts->second_part = q.begin_ts.tv_usec;
+		break;
+	}
+	case VTQ_COMMIT_TS: {
+		MYSQL_TIME* out_ts = reinterpret_cast<MYSQL_TIME *>(out);
+		thd_get_timezone(thd)->gmt_sec_to_TIME(out_ts, q.commit_ts.tv_sec);
+		out_ts->second_part = q.commit_ts.tv_usec;
+		break;
+	}
+	case VTQ_ISO_LEVEL:
+		*reinterpret_cast<uint *>(out) = q.iso_level;
+		break;
+	default:
+		ut_error;
+	}
+}
+
+inline
+const char *
+vtq_query_t::cache_result(mem_heap_t* heap, const rec_t* rec)
+{
+	prev_query.tv_sec = 0;
+	return dict_process_sys_vtq(heap, rec, result);
+}
+
+
+/** Query VTQ by TRX_ID.
+@param[in]	thd	MySQL thread
+@param[out]	out	field value or whole record returned by query (selected by `field`)
+@param[in]	in_trx_id query parameter TRX_ID
+@param[in]	field	field to get in `out` or VTQ_ALL for whole record (vtq_record_t)
+@return	TRUE if record is found, FALSE otherwise */
+UNIV_INTERN
+bool
+vtq_query_trx_id(THD* thd, void *out, ulonglong _in_trx_id, vtq_field_t field)
+{
+	trx_t*		trx;
+	dict_index_t*	index;
+	btr_pcur_t	pcur;
+	dtuple_t*	tuple;
+	dfield_t*	dfield;
+	trx_id_t	trx_id_net;
+	mtr_t		mtr;
+	mem_heap_t*	heap;
+	rec_t*		rec;
+	bool		found = false;
+
+	DBUG_ENTER("vtq_query_trx_id");
+
+	if (_in_trx_id == 0) {
+		DBUG_RETURN(false);
+	}
+
+	ut_ad(sizeof(_in_trx_id) == sizeof(trx_id_t));
+	trx_id_t	in_trx_id = static_cast<trx_id_t>(_in_trx_id);
+
+	trx = thd_to_trx(thd);
+	ut_a(trx);
+
+	vtq_record_t	&cached = trx->vtq_query.result;
+
+	if (cached.trx_id == in_trx_id) {
+		vtq_result(thd, cached, out, field);
+		DBUG_RETURN(true);
+	}
+
+	index = dict_table_get_first_index(dict_sys->sys_vtq);
+	heap = mem_heap_create(0);
+
+	ut_ad(index);
+	ut_ad(dict_index_is_clust(index));
+
+	mach_write_to_8(
+		reinterpret_cast<byte*>(&trx_id_net),
+		in_trx_id);
+
+	tuple = dtuple_create(heap, 1);
+	dfield = dtuple_get_nth_field(tuple, DICT_FLD__SYS_VTQ__TRX_ID);
+	dfield_set_data(dfield, &trx_id_net, 8);
+	dict_index_copy_types(tuple, index, 1);
+
+	mtr_start_trx(&mtr, trx);
+	btr_pcur_open_on_user_rec(index, tuple, PAGE_CUR_GE,
+			BTR_SEARCH_LEAF, &pcur, &mtr);
+
+	if (!btr_pcur_is_on_user_rec(&pcur))
+		goto not_found;
+
+	rec = btr_pcur_get_rec(&pcur);
+	{
+		const char *err = trx->vtq_query.cache_result(heap, rec);
+		if (err) {
+			fprintf(stderr, "InnoDB: vtq_query_trx_id: get VTQ field failed: %s\n", err);
+			ut_ad(false && "get VTQ field failed");
+			goto not_found;
+		}
+	}
+
+	if (cached.trx_id != in_trx_id)
+		goto not_found;
+
+	vtq_result(thd, cached, out, field);
+	found = true;
+
+not_found:
+	btr_pcur_close(&pcur);
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
+
+	DBUG_RETURN(found);
+}
+
+static
+inline
+void rec_get_timeval(const rec_t* rec, ulint nfield, timeval& out)
+{
+	ulint		len;
+	const byte*	field;
+	field = rec_get_nth_field_old(
+		rec, nfield, &len);
+
+	ut_ad(len == sizeof(ullong));
+
+	out.tv_sec = mach_read_from_4(field);
+	out.tv_usec = mach_read_from_4(field + 4);
+}
+
+inline
+const char *
+vtq_query_t::cache_result(
+	mem_heap_t* heap,
+	const rec_t* rec,
+	const timeval& _ts_query,
+	bool _backwards)
+{
+	prev_query = _ts_query;
+	backwards = _backwards;
+	return dict_process_sys_vtq(heap, rec, result);
+}
+
+static
+inline
+bool
+operator== (const timeval &a, const timeval &b)
+{
+	return a.tv_sec == b.tv_sec && a.tv_usec == b.tv_usec;
+}
+
+static
+inline
+bool
+operator> (const timeval &a, const timeval &b)
+{
+	return a.tv_sec > b.tv_sec || (a.tv_sec == b.tv_sec && a.tv_usec > b.tv_usec);
+}
+
+static
+inline
+bool
+operator< (const timeval &a, const timeval &b)
+{
+	return b > a;
+}
+
+
+/** Query VTQ by COMMIT_TS.
+@param[in]	thd	MySQL thread
+@param[out]	out	field value or whole record returned by query (selected by `field`)
+@param[in]	commit_ts query parameter COMMIT_TS
+@param[in]	field	field to get in `out` or VTQ_ALL for whole record (vtq_record_t)
+@param[in]	backwards direction of VTQ search
+@return	TRUE if record is found, FALSE otherwise */
+UNIV_INTERN
+bool
+vtq_query_commit_ts(
+	THD* thd,
+	void *out,
+	const MYSQL_TIME &_commit_ts,
+	vtq_field_t field,
+	bool backwards)
+{
+	trx_t*		trx;
+	btr_pcur_t	pcur;
+	dtuple_t*	tuple;
+	page_cur_mode_t mode;
+	mtr_t		mtr;
+	mem_heap_t*	heap;
+	uint		err;
+	timeval		commit_ts;
+	timeval		rec_ts = { 0, 0 };
+	const rec_t	*rec, *clust_rec;
+	dict_index_t*	index = dict_sys->vtq_commit_ts_ind;
+	dict_index_t*	clust_index;
+	bool		found = false;
+
+	DBUG_ENTER("vtq_query_commit_ts");
+
+	mode = backwards ? PAGE_CUR_LE : PAGE_CUR_GE;
+
+	trx = thd_to_trx(thd);
+	ut_a(trx);
+
+	vtq_record_t &cached = trx->vtq_query.result;
+	timeval &prev_query = trx->vtq_query.prev_query;
+	bool prev_bwds = trx->vtq_query.backwards;
+
+	commit_ts.tv_usec = _commit_ts.second_part;
+	commit_ts.tv_sec = thd_get_timezone(thd)->TIME_to_gmt_sec(&_commit_ts, &err);
+	if (err) {
+		if (err == ER_WARN_DATA_OUT_OF_RANGE) {
+			if (_commit_ts.year <= TIMESTAMP_MIN_YEAR) {
+				commit_ts.tv_usec = 0;
+				commit_ts.tv_sec = 1;
+			} else {
+				ut_ad(_commit_ts.year >= TIMESTAMP_MAX_YEAR);
+				commit_ts.tv_usec = TIME_MAX_SECOND_PART;
+				commit_ts.tv_sec = MY_TIME_T_MAX;
+			}
+		} else {
+			DBUG_RETURN(false);
+		}
+	} else if (cached.commit_ts == commit_ts ||
+		(prev_query.tv_sec && prev_bwds == backwards && (
+			(!backwards && (commit_ts < prev_query) && commit_ts > cached.commit_ts) ||
+			(backwards && (commit_ts > prev_query) && commit_ts < cached.commit_ts))))
+	{
+		vtq_result(thd, cached, out, field);
+		DBUG_RETURN(true);
+	}
+
+	heap = mem_heap_create(0);
+
+	tuple = dtuple_create(heap, 1);
+	dict_index_copy_types(tuple, index, 1);
+	dtuple_get_nth_field(tuple, 0)->len = UNIV_SQL_NULL;
+	set_tuple_col_8(tuple, 0, commit_ts, heap);
+
+	mtr_start_trx(&mtr, trx);
+	btr_pcur_open_on_user_rec(index, tuple, mode,
+			BTR_SEARCH_LEAF, &pcur, &mtr);
+
+	if (btr_pcur_is_on_user_rec(&pcur)) {
+		rec = btr_pcur_get_rec(&pcur);
+		rec_get_timeval(rec, 0, rec_ts);
+
+		if (rec_ts.tv_sec == commit_ts.tv_sec
+		&& rec_ts.tv_usec == commit_ts.tv_usec)
+			goto found;
+	} else {
+		rec_ts = commit_ts;
+	}
+
+	if (mode == PAGE_CUR_GE) {
+		btr_pcur_move_to_prev_user_rec(&pcur, &mtr);
+	} else {
+		btr_pcur_move_to_next_user_rec(&pcur, &mtr);
+	}
+
+	if (!btr_pcur_is_on_user_rec(&pcur))
+		goto not_found;
+
+	rec = btr_pcur_get_rec(&pcur);
+found:
+	clust_rec = row_get_clust_rec(BTR_SEARCH_LEAF, rec, index, &clust_index, &mtr);
+	if (!clust_rec) {
+		fprintf(stderr, "InnoDB: vtq_query_commit_ts: secondary index is out of sync\n");
+		ut_ad(false && "secondary index is out of sync");
+		goto not_found;
+	}
+
+	{
+		const char *err =
+			trx->vtq_query.cache_result(
+				heap,
+				clust_rec,
+				rec_ts,
+				backwards);
+		if (err) {
+			fprintf(stderr, "InnoDB: vtq_query_commit_ts: get VTQ field failed: %s\n", err);
+			ut_ad(false && "get VTQ field failed");
+			goto not_found;
+		}
+	}
+	vtq_result(thd, cached, out, field);
+	found = true;
+
+not_found:
+	btr_pcur_close(&pcur);
+	mtr_commit(&mtr);
+	mem_heap_free(heap);
+
+	DBUG_RETURN(found);
+}
+
+/** Check if transaction TX1 sees transaction TX0.
+@param[in]	thd	MySQL thread
+@param[out]	result	true if TX1 sees TX0
+@param[in]	trx_id1	TX1 TRX_ID
+@param[in]	trx_id0	TX0 TRX_ID
+@param[in]	commit_id1 TX1 COMMIT_ID
+@param[in]	iso_level1 TX1 isolation level
+@param[in]	commit_id0 TX0 COMMIT_ID
+@return	FALSE if there is no trx_id1 in VTQ, otherwise TRUE */
+bool
+vtq_trx_sees(
+	THD *thd,
+	bool &result,
+	ulonglong trx_id1,
+	ulonglong trx_id0,
+	ulonglong commit_id1,
+	uchar iso_level1,
+	ulonglong commit_id0)
+{
+	DBUG_ENTER("vtq_trx_sees");
+
+	if (trx_id1 == trx_id0) {
+		result = false;
+		DBUG_RETURN(true);
+	}
+
+	if (trx_id1 == ULONGLONG_MAX || trx_id0 == 0) {
+		result = true;
+		DBUG_RETURN(true);
+	}
+
+	static const char* msg_cant_find = "InnoDB: vtq_trx_sees: can't find COMMIT_ID%c by TRX_ID: %llu\n";
+	if (!commit_id1) {
+		if (!vtq_query_trx_id(thd, NULL, trx_id1, VTQ_ALL)) {
+			fprintf(stderr, msg_cant_find, '1', trx_id1);
+			DBUG_RETURN(false);
+		}
+		trx_t* trx = thd_to_trx(thd);
+		ut_ad(trx);
+		commit_id1 = trx->vtq_query.result.commit_id;
+		iso_level1 = trx->vtq_query.result.iso_level;
+	}
+
+	if (!commit_id0) {
+		if (!vtq_query_trx_id(thd, &commit_id0, trx_id0, VTQ_COMMIT_ID)) {
+			fprintf(stderr, msg_cant_find, '0', trx_id0);
+			DBUG_RETURN(false);
+		}
+	}
+
+	// Trivial case: TX1 started after TX0 committed
+	if (trx_id1 > commit_id0
+		// Concurrent transactions: TX1 committed after TX0 and TX1 is read (un)committed
+		|| (commit_id1 > commit_id0 && iso_level1 < TRX_ISO_REPEATABLE_READ))
+	{
+		result = true;
+	} else {
+		// All other cases: TX1 does not see TX0
+		result = false;
+	}
+
+	DBUG_RETURN(true);
+}