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MDEV-12137 DELETE statement with the same source and target

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single-table deletes only
This commit is contained in:
halfspawn
2017-07-07 17:50:09 +02:00
committed by Sergei Golubchik
parent 30fee6150a
commit abf95afa2a
18 changed files with 529 additions and 74 deletions
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88
sql/sql_delete.cc
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@ -45,6 +45,8 @@
// end_read_record
#include "sql_partition.h" // make_used_partitions_str
#define MEM_STRIP_BUF_SIZE current_thd->variables.sortbuff_size
/*
@brief
Print query plan of a single-table DELETE command
@ -246,6 +248,9 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
Delete_plan query_plan(thd->mem_root);
query_plan.index= MAX_KEY;
query_plan.using_filesort= FALSE;
Unique * deltempfile= NULL;
uint delete_while_scanning= 1;
uint delete_record= 0;
DBUG_ENTER("mysql_delete");
create_explain_query(thd->lex, thd->mem_root);
@ -275,7 +280,8 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
query_plan.updating_a_view= MY_TEST(table_list->view);
if (mysql_prepare_delete(thd, table_list, select_lex->with_wild,
select_lex->item_list, &conds))
select_lex->item_list, &conds,
delete_while_scanning))
DBUG_RETURN(TRUE);
if (with_select)
@ -556,16 +562,68 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
explain= (Explain_delete*)thd->lex->explain->get_upd_del_plan();
explain->tracker.on_scan_init();
while (!(error=info.read_record(&info)) && !thd->killed &&
! thd->is_error())
if (delete_while_scanning == 0)
{
explain->tracker.on_record_read();
thd->inc_examined_row_count(1);
if (table->vfield)
(void) table->update_virtual_fields(table->file, VCOL_UPDATE_FOR_DELETE);
if (!select || select->skip_record(thd) > 0)
/*
The table we are going to delete appears in join.
Instead of deleting the rows, first mark them deleted.
*/
ha_rows tmplimit=limit;
deltempfile= new Unique (refpos_order_cmp,
(void *) table->file,
table->file->ref_length,
MEM_STRIP_BUF_SIZE);
while (!(error=info.read_record(&info)) && !thd->killed &&
! thd->is_error())
{
explain->tracker.on_record_read();
thd->inc_examined_row_count(1);
if (table->vfield)
(void) table->update_virtual_fields(table->file,
VCOL_UPDATE_FOR_DELETE);
if (!select || select->skip_record(thd) > 0)
{
explain->tracker.on_record_after_where();
table->file->position(table->record[0]);
if ((error= deltempfile->unique_add((char*) table->file->ref)))
{
error= 1;
goto terminate_delete;
}
if (!--tmplimit && using_limit)
{
break;
}
}
}
end_read_record(&info);
if (deltempfile->get(table) ||
table->file->ha_index_or_rnd_end() ||
init_read_record(&info, thd, table, NULL , &deltempfile->sort, 0, 1,
FALSE))
{
error= 1;
goto terminate_delete;
}
delete_record= 1;
}
while (!(error=info.read_record(&info)) && !thd->killed &&
! thd->is_error())
{
if (delete_while_scanning == 1)
{
explain->tracker.on_record_read();
thd->inc_examined_row_count(1);
if (table->vfield)
(void) table->update_virtual_fields(table->file,
VCOL_UPDATE_FOR_DELETE);
delete_record=(!select || select->skip_record(thd) > 0) ? 1 : 0;
if (delete_record)
explain->tracker.on_record_after_where();
}
if (delete_record == 1)
{
explain->tracker.on_record_after_where();
if (table->triggers &&
table->triggers->process_triggers(thd, TRG_EVENT_DELETE,
TRG_ACTION_BEFORE, FALSE))
@ -616,6 +674,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
else
break;
}
terminate_delete:
killed_status= thd->killed;
if (killed_status != NOT_KILLED || thd->is_error())
error= 1; // Aborted
@ -647,6 +706,8 @@ cleanup:
thd->lex->current_select->first_cond_optimization= 0;
}
delete deltempfile;
deltempfile=NULL;
delete select;
select= NULL;
transactional_table= table->file->has_transactions();
@ -746,7 +807,8 @@ l
TRUE error
*/
int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list,
uint wild_num, List<Item> &field_list, Item **conds)
uint wild_num, List<Item> &field_list, Item **conds,
uint &delete_while_scanning)
{
Item *fake_conds= 0;
SELECT_LEX *select_lex= &thd->lex->select_lex;
@ -775,10 +837,7 @@ l
{
TABLE_LIST *duplicate;
if ((duplicate= unique_table(thd, table_list, table_list->next_global, 0)))
{
update_non_unique_table_error(table_list, "DELETE", duplicate);
DBUG_RETURN(TRUE);
}
delete_while_scanning= 0;
}
if (select_lex->inner_refs_list.elements &&
@ -794,7 +853,6 @@ l
Delete multiple tables from join
***************************************************************************/
#define MEM_STRIP_BUF_SIZE current_thd->variables.sortbuff_size
extern "C" int refpos_order_cmp(void* arg, const void *a,const void *b)
{