Merge 10.0-base -> 10.0

1 files changed, 231 insertions, 16 deletions

diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index 1e0789aab12..1500f1615fb 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -40,6 +40,161 @@
 #include "records.h"                            // init_read_record,
 #include "sql_derived.h"                        // mysql_handle_list_of_derived
                                                 // end_read_record
+#include "sql_partition.h"       // make_used_partitions_str
+
+/*
+  @brief
+    Print query plan of a single-table DELETE command
+  
+  @detail
+    This function is used by EXPLAIN DELETE and by SHOW EXPLAIN when it is
+    invoked on a running DELETE statement.
+*/
+
+void Delete_plan::save_explain_data(Explain_query *query)
+{
+  Explain_delete* explain= new Explain_delete;
+
+  if (deleting_all_rows)
+  {
+    explain->deleting_all_rows= true;
+    explain->select_type= "SIMPLE";
+    explain->rows= scanned_rows;
+  }
+  else
+  {
+    explain->deleting_all_rows= false;
+    Update_plan::save_explain_data_intern(query, explain);
+  }
+ 
+  query->add_upd_del_plan(explain);
+}
+
+
+void Update_plan::save_explain_data(Explain_query *query)
+{
+  Explain_update* explain= new Explain_update;
+  save_explain_data_intern(query, explain);
+  query->add_upd_del_plan(explain);
+}
+
+
+void Update_plan::save_explain_data_intern(Explain_query *query, 
+                                           Explain_update *explain)
+{
+  explain->select_type= "SIMPLE";
+  explain->table_name.append(table->pos_in_table_list->alias);
+  
+  explain->impossible_where= false;
+  explain->no_partitions= false;
+
+  if (impossible_where)
+  {
+    explain->impossible_where= true;
+    return;
+  }
+
+  if (no_partitions)
+  {
+    explain->no_partitions= true;
+    return;
+  }
+  
+  select_lex->set_explain_type(TRUE);
+  explain->select_type= select_lex->type;
+  /* Partitions */
+  {
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+    partition_info *part_info;
+    if ((part_info= table->part_info))
+    {          
+      make_used_partitions_str(part_info, &explain->used_partitions);
+      explain->used_partitions_set= true;
+    }
+    else
+      explain->used_partitions_set= false;
+#else
+    /* just produce empty column if partitioning is not compiled in */
+    explain->used_partitions_set= false;
+#endif
+  }
+
+
+  /* Set jtype */
+  if (select && select->quick)
+  {
+    int quick_type= select->quick->get_type();
+    if ((quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE) ||
+        (quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_INTERSECT) ||
+        (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT) ||
+        (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION))
+      explain->jtype= JT_INDEX_MERGE;
+    else
+      explain->jtype= JT_RANGE;
+  }
+  else
+  {
+    if (index == MAX_KEY)
+      explain->jtype= JT_ALL;
+    else
+      explain->jtype= JT_NEXT;
+  }
+
+  explain->using_where= test(select && select->cond);
+  explain->using_filesort= using_filesort;
+  explain->using_io_buffer= using_io_buffer;
+
+  make_possible_keys_line(table, possible_keys, &explain->possible_keys_line);
+
+  explain->quick_info= NULL;
+
+  /* Calculate key_len */
+  if (select && select->quick)
+  {
+    explain->quick_info= select->quick->get_explain(mem_root);
+  }
+  else
+  {
+    if (index != MAX_KEY)
+    {
+      explain->key_str.append(table->key_info[index].name);
+      char buf[64];
+      size_t length;
+      length= longlong10_to_str(table->key_info[index].key_length, buf, 10) - buf;
+      explain->key_len_str.append(buf, length);
+    }
+  }
+  explain->rows= scanned_rows;
+
+  if (select && select->quick && 
+      select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_RANGE)
+  {
+    explain_append_mrr_info((QUICK_RANGE_SELECT*)select->quick, 
+                            &explain->mrr_type);
+  }
+
+  bool skip= updating_a_view;
+
+  /* Save subquery children */
+  for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit();
+       unit;
+       unit= unit->next_unit())
+  {
+    if (skip)
+    {
+      skip= false;
+      continue;
+    }
+    /* 
+      Display subqueries only if they are not parts of eliminated WHERE/ON
+      clauses.
+    */
+    if (!(unit->item && unit->item->eliminated))
+      explain->add_child(unit->first_select()->select_number);
+  }
+}
+
+
 /**
   Implement DELETE SQL word.
 
@@ -64,13 +219,16 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   bool          reverse= FALSE;
   ORDER *order= (ORDER *) ((order_list && order_list->elements) ?
                            order_list->first : NULL);
-  uint usable_index= MAX_KEY;
   SELECT_LEX   *select_lex= &thd->lex->select_lex;
   killed_state killed_status= NOT_KILLED;
   THD::enum_binlog_query_type query_type= THD::ROW_QUERY_TYPE;
   bool with_select= !select_lex->item_list.is_empty();
+  Delete_plan query_plan(thd->mem_root);
+  query_plan.index= MAX_KEY;
+  query_plan.using_filesort= FALSE;
   DBUG_ENTER("mysql_delete");
 
+  create_explain_query(thd->lex, thd->mem_root);
   if (open_and_lock_tables(thd, table_list, TRUE, 0))
     DBUG_RETURN(TRUE);
 
@@ -92,6 +250,9 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   }
   THD_STAGE_INFO(thd, stage_init);
   table->map=1;
+  query_plan.select_lex= &thd->lex->select_lex;
+  query_plan.table= table;
+  query_plan.updating_a_view= test(table_list->view);
 
   if (mysql_prepare_delete(thd, table_list, select_lex->with_wild,
                                             select_lex->item_list, &conds))
@@ -168,6 +329,11 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
     ha_rows const maybe_deleted= table->file->stats.records;
     DBUG_PRINT("debug", ("Trying to use delete_all_rows()"));
+
+    query_plan.set_delete_all_rows(maybe_deleted);
+    if (thd->lex->describe)
+      goto exit_without_my_ok;
+
     if (!(error=table->file->ha_delete_all_rows()))
     {
       /*
@@ -192,14 +358,23 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     Item::cond_result result;
     conds= remove_eq_conds(thd, conds, &result);
     if (result == Item::COND_FALSE)             // Impossible where
+    {
       limit= 0;
+      query_plan.set_impossible_where();
+      if (thd->lex->describe)
+        goto exit_without_my_ok;
+    }
   }
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE
   if (prune_partitions(thd, table, conds))
   {
     free_underlaid_joins(thd, select_lex);
-    // No matching record
+
+    query_plan.set_no_partitions();
+    if (thd->lex->describe)
+      goto exit_without_my_ok;
+
     my_ok(thd, 0);
     DBUG_RETURN(0);
   }
@@ -216,6 +391,10 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     DBUG_RETURN(TRUE);
   if ((select && select->check_quick(thd, safe_update, limit)) || !limit)
   {
+    query_plan.set_impossible_where();
+    if (thd->lex->describe)
+      goto exit_without_my_ok;
+
     delete select;
     free_underlaid_joins(thd, select_lex);
     /* 
@@ -246,28 +425,54 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   if (options & OPTION_QUICK)
     (void) table->file->extra(HA_EXTRA_QUICK);
 
+  query_plan.scanned_rows= select? select->records: table->file->stats.records;
   if (order)
   {
-    uint         length= 0;
-    SORT_FIELD  *sortorder;
-    ha_rows examined_rows;
-    ha_rows found_rows;
-    
     table->update_const_key_parts(conds);
     order= simple_remove_const(order, conds);
 
-    bool need_sort;
     if (select && select->quick && select->quick->unique_key_range())
     { // Single row select (always "ordered")
-      need_sort= FALSE;
-      usable_index= MAX_KEY;
+      query_plan.using_filesort= FALSE;
+      query_plan.index= MAX_KEY;
     }
     else
-      usable_index= get_index_for_order(order, table, select, limit,
-                                        &need_sort, &reverse);
-    if (need_sort)
     {
-      DBUG_ASSERT(usable_index == MAX_KEY);
+      ha_rows scanned_limit= query_plan.scanned_rows;
+      query_plan.index= get_index_for_order(order, table, select, limit,
+                                            &scanned_limit,
+                                            &query_plan.using_filesort, 
+                                            &reverse);
+      if (!query_plan.using_filesort)
+        query_plan.scanned_rows= scanned_limit;
+    }
+  }
+
+  query_plan.select= select;
+  query_plan.possible_keys= select? select->possible_keys: key_map(0);
+  
+  /*
+    Ok, we have generated a query plan for the DELETE.
+     - if we're running EXPLAIN DELETE, goto produce explain output 
+     - otherwise, execute the query plan
+  */
+  if (thd->lex->describe)
+    goto exit_without_my_ok;
+  
+  query_plan.save_explain_data(thd->lex->explain);
+
+  DBUG_EXECUTE_IF("show_explain_probe_delete_exec_start", 
+                  dbug_serve_apcs(thd, 1););
+
+  if (query_plan.using_filesort)
+  {
+    ha_rows examined_rows;
+    ha_rows found_rows;
+    uint         length= 0;
+    SORT_FIELD  *sortorder;
+
+    {
+      DBUG_ASSERT(query_plan.index == MAX_KEY);
       table->sort.io_cache= (IO_CACHE *) my_malloc(sizeof(IO_CACHE),
                                                    MYF(MY_FAE | MY_ZEROFILL |
                                                        MY_THREAD_SPECIFIC));
@@ -301,7 +506,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     free_underlaid_joins(thd, select_lex);
     DBUG_RETURN(TRUE);
   }
-  if (usable_index == MAX_KEY || (select && select->quick))
+  if (query_plan.index == MAX_KEY || (select && select->quick))
   {
     if (init_read_record(&info, thd, table, select, 1, 1, FALSE))
     {
@@ -311,7 +516,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
     }
   }
   else
-    init_read_record_idx(&info, thd, table, 1, usable_index, reverse);
+    init_read_record_idx(&info, thd, table, 1, query_plan.index, reverse);
 
   init_ftfuncs(thd, select_lex, 1);
   THD_STAGE_INFO(thd, stage_updating);
@@ -479,6 +684,16 @@ cleanup:
     DBUG_PRINT("info",("%ld records deleted",(long) deleted));
   }
   DBUG_RETURN(error >= 0 || thd->is_error());
+  
+  /* Special exits */
+exit_without_my_ok:
+  query_plan.save_explain_data(thd->lex->explain);
+  int err2= thd->lex->explain->send_explain(thd);
+
+  delete select;
+  free_underlaid_joins(thd, select_lex);
+  //table->set_keyread(false);
+  DBUG_RETURN((err2 || thd->is_error() || thd->killed) ? 1 : 0);
 }