Commit 0695239a authored by unknown's avatar unknown

A better fix for UNION and slow query log.


sql/sql_union.cc:
  A better fix for UNION and slow query log.
  This patch also fixes some indentation issues
parent f390da22
/* Copyright (C) 2000 MySQL AB
/* Copyright (C) 2000-2003 MySQL AB
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
......@@ -68,6 +68,7 @@ int select_union::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
return 0;
}
bool select_union::send_data(List<Item> &values)
{
if (unit->offset_limit_cnt)
......@@ -91,11 +92,13 @@ bool select_union::send_data(List<Item> &values)
return 0;
}
bool select_union::send_eof()
{
return 0;
}
bool select_union::flush()
{
int error;
......@@ -108,9 +111,13 @@ bool select_union::flush()
return 0;
}
int st_select_lex_unit::prepare(THD *thd, select_result *result,
int st_select_lex_unit::prepare(THD *thd, select_result *sel_result,
bool tables_and_fields_initied)
{
SELECT_LEX_NODE *lex_select_save= thd->lex.current_select;
SELECT_LEX *select_cursor;
TMP_TABLE_PARAM tmp_table_param;
DBUG_ENTER("st_select_lex_unit::prepare");
if (prepared)
......@@ -118,11 +125,8 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
prepared= 1;
res= 0;
found_rows_for_union= 0;
TMP_TABLE_PARAM tmp_table_param;
this->result= result;
result= sel_result;
t_and_f= tables_and_fields_initied;
SELECT_LEX_NODE *lex_select_save= thd->lex.current_select;
SELECT_LEX *select_cursor;
thd->lex.current_select= select_cursor= first_select_in_union();
/* Global option */
......@@ -144,7 +148,8 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
TABLE_LIST *first_table= (TABLE_LIST*) select_cursor->table_list.first;
if (setup_tables(first_table) ||
setup_wild(thd, first_table, select_cursor->item_list, 0, select_cursor->with_wild))
setup_wild(thd, first_table, select_cursor->item_list, 0,
select_cursor->with_wild))
goto err;
List_iterator<Item> it(select_cursor->item_list);
Item *item;
......@@ -156,8 +161,8 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
(item_list.elements + select_cursor->with_sum_func +
select_cursor->order_list.elements +
select_cursor->group_list.elements)) ||
setup_fields(thd, select_cursor->ref_pointer_array, first_table, item_list,
0, 0, 1))
setup_fields(thd, select_cursor->ref_pointer_array, first_table,
item_list, 0, 0, 1))
goto err;
t_and_f= 1;
}
......@@ -183,11 +188,11 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
union_result->not_describe=1;
union_result->tmp_table_param=&tmp_table_param;
/*
the following piece of code is placed here solely for the purpose of
getting correct results with EXPLAIN when UNION is withing a sub-select
or derived table ...
*/
/*
The following piece of code is placed here solely for the purpose of
getting correct results with EXPLAIN when UNION is withing a sub-select
or derived table ...
*/
if (thd->lex.describe)
{
......@@ -216,7 +221,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
(ORDER*) NULL,
sl, this, t_and_f);
t_and_f= 0;
if (res | thd->is_fatal_error)
if (res || thd->is_fatal_error)
goto err;
}
}
......@@ -235,7 +240,7 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
}
}
DBUG_RETURN(res | thd->is_fatal_error);
DBUG_RETURN(res || thd->is_fatal_error ? 1 : 0);
err:
thd->lex.current_select= lex_select_save;
DBUG_RETURN(-1);
......@@ -244,17 +249,18 @@ int st_select_lex_unit::prepare(THD *thd, select_result *result,
int st_select_lex_unit::exec()
{
DBUG_ENTER("st_select_lex_unit::exec");
int do_print_slow= 0;
SELECT_LEX_NODE *lex_select_save= thd->lex.current_select;
SELECT_LEX *select_cursor=first_select_in_union(), *last_select;
DBUG_ENTER("st_select_lex_unit::exec");
LINT_INIT(last_select);
bool do_print_slow=0;
if (executed && !(dependent || uncacheable))
DBUG_RETURN(0);
executed= 1;
if ((dependent||uncacheable) || !item || !item->assigned())
if ((dependent || uncacheable) || !item || !item->assigned())
{
if (optimized && item && item->assigned())
{
......@@ -314,7 +320,7 @@ int st_select_lex_unit::exec()
thd->lex.current_select= lex_select_save;
DBUG_RETURN(res);
}
do_print_slow = do_print_slow || (select_cursor->options & (QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED));
do_print_slow|= select_cursor->options;
}
}
optimized= 1;
......@@ -322,8 +328,8 @@ int st_select_lex_unit::exec()
/* Send result to 'result' */
// to correct ORDER BY reference resolving
thd->lex.current_select = select_cursor;
res =-1;
thd->lex.current_select= select_cursor;
res= -1;
{
List<Item_func_match> empty_list;
empty_list.empty();
......@@ -332,9 +338,11 @@ int st_select_lex_unit::exec()
{
SELECT_LEX *fake_select = new SELECT_LEX();
fake_select->make_empty_select(last_select);
offset_limit_cnt= (select_cursor->braces) ? global_parameters->offset_limit : 0;
select_limit_cnt= (select_cursor->braces) ? global_parameters->select_limit+
global_parameters->offset_limit : HA_POS_ERROR;
offset_limit_cnt= (select_cursor->braces ?
global_parameters->offset_limit : 0);
select_limit_cnt= (select_cursor->braces ?
global_parameters->select_limit+
global_parameters->offset_limit : HA_POS_ERROR);
if (select_limit_cnt < global_parameters->select_limit)
select_limit_cnt= HA_POS_ERROR; // no limit
if (select_limit_cnt == HA_POS_ERROR)
......@@ -351,14 +359,23 @@ int st_select_lex_unit::exec()
thd->limit_found_rows = (ulonglong)table->file->records;
fake_select->exclude();
delete fake_select;
if (select_cursor == &thd->lex.select_lex && !do_print_slow)
select_cursor->options &= ~(QUERY_NO_INDEX_USED | QUERY_NO_GOOD_INDEX_USED);
/*
Mark for slow query log if any of the union parts didn't use
indexes efficiently
*/
select_cursor->options= ((select_cursor->options &
~(QUERY_NO_INDEX_USED |
QUERY_NO_GOOD_INDEX_USED)) |
do_print_slow &
(QUERY_NO_INDEX_USED |
QUERY_NO_GOOD_INDEX_USED));
}
}
thd->lex.current_select= lex_select_save;
DBUG_RETURN(res);
}
int st_select_lex_unit::cleanup()
{
int error= 0;
......
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