Merge spetrunia@bk-internal.mysql.com:/home/bk/mysql-5.0-opt (3c9594b0) · Commits · Software / OSDI20 Artifacts / mariadb

sql/sql_select.cc

+1 −1

Original line number	Diff line number	Diff line
		@@ -2417,7 +2417,7 @@ make_join_statistics(JOIN join, TABLE_LIST tables, COND *conds,

		if ((table->s->system \|\| table->file->records <= 1) && ! s->dependent &&
		!(table->file->table_flags() & HA_NOT_EXACT_COUNT) &&
		!table->fulltext_searched)
		!table->fulltext_searched && !join->no_const_tables)
		{
		set_position(join,const_count++,s,(KEYUSE*) 0);
		}

sql/sql_select.h

+10 −0

Original line number	Diff line number	Diff line
		@@ -277,6 +277,14 @@ class JOIN :public Sql_alloc
		SELECT_LEX_UNIT *unit;
		// select that processed
		SELECT_LEX *select_lex;
		/*
		TRUE <=> optimizer must not mark any table as a constant table.
		This is needed for subqueries in form "a IN (SELECT .. UNION SELECT ..):
		when we optimize the select that reads the results of the union from a
		temporary table, we must not mark the temp. table as constant because
		the number of rows in it may vary from one subquery execution to another.
		*/
		bool no_const_tables;

		JOIN *tmp_join; // copy of this JOIN to be used with temporary tables
		ROLLUP rollup; // Used with rollup
		@@ -406,6 +414,8 @@ class JOIN :public Sql_alloc
		tmp_table_param.init();
		tmp_table_param.end_write_records= HA_POS_ERROR;
		rollup.state= ROLLUP::STATE_NONE;

		no_const_tables= FALSE;
		}

		int prepare(Item **rref_pointer_array, TABLE_LIST tables, uint wind_num,

sql/sql_union.cc

+40 −17

Original line number	Diff line number	Diff line
		@@ -545,6 +545,10 @@ bool st_select_lex_unit::exec()
		/*
		allocate JOIN for fake select only once (prevent
		mysql_select automatic allocation)
		TODO: The above is nonsense. mysql_select() will not allocate the
		join if one already exists. There must be some other reason why we
		don't let it allocate the join. Perhaps this is because we need
		some special parameter values passed to join constructor?
		*/
		if (!(fake_select_lex->join= new JOIN(thd, item_list,
		fake_select_lex->options, result)))
		@@ -552,25 +556,36 @@ bool st_select_lex_unit::exec()
		fake_select_lex->table_list.empty();
		DBUG_RETURN(TRUE);
		}
		fake_select_lex->join->no_const_tables= TRUE;

		/*
		Fake st_select_lex should have item list for correctref_array
		allocation.
		*/
		fake_select_lex->item_list= item_list;
		saved_error= mysql_select(thd, &fake_select_lex->ref_pointer_array,
		&result_table_list,
		0, item_list, NULL,
		global_parameters->order_list.elements,
		(ORDER*)global_parameters->order_list.first,
		(ORDER) NULL, NULL, (ORDER) NULL,
		fake_select_lex->options \| SELECT_NO_UNLOCK,
		result, this, fake_select_lex);
		}
		else
		{
		JOIN_TAB tab,end;
		for (tab=join->join_tab, end=tab+join->tables ;
		tab && tab != end ;
		tab++)
		if (describe)
		{
		delete tab->select;
		delete tab->quick;
		}
		/*
		In EXPLAIN command, constant subqueries that do not use any
		tables are executed two times:
		- 1st time is a real evaluation to get the subquery value
		- 2nd time is to produce EXPLAIN output rows.
		1st execution sets certain members (e.g. select_result) to perform
		subquery execution rather than EXPLAIN line production. In order
		to reset them back, we re-do all of the actions (yes it is ugly):
		*/
		join->init(thd, item_list, fake_select_lex->options, result);
		}
		saved_error= mysql_select(thd, &fake_select_lex->ref_pointer_array,
		&result_table_list,
		0, item_list, NULL,
		@@ -579,6 +594,14 @@ bool st_select_lex_unit::exec()
		(ORDER) NULL, NULL, (ORDER) NULL,
		fake_select_lex->options \| SELECT_NO_UNLOCK,
		result, this, fake_select_lex);
		}
		else
		{
		join->examined_rows= 0;
		join->reinit();
		saved_error= join->exec();
		}
		}

		fake_select_lex->table_list.empty();
		if (!saved_error)