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Merge

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bell@sanja.is.com.ua
2004-05-14 13:33:02 +03:00
parent a71771788e 8885ce0dd7
commit 71a374dc13
11 changed files with 177 additions and 72 deletions
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34
sql/sql_union.cc
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@ -41,7 +41,7 @@ int mysql_union(THD *thd, LEX *lex, select_result *result,
***************************************************************************/
select_union::select_union(TABLE *table_par)
:table(table_par), not_describe(0)
:table(table_par)
{
bzero((char*) &info,sizeof(info));
/*
@ -149,6 +149,8 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
select_result *tmp_result;
DBUG_ENTER("st_select_lex_unit::prepare");
describe= test(additional_options & SELECT_DESCRIBE);
/*
result object should be reassigned even if preparing already done for
max/min subquery (ALL/ANY optimization)
@ -156,7 +158,26 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
result= sel_result;
if (prepared)
{
if (describe)
{
/* fast reinit for EXPLAIN */
for (sl= first_select_in_union(); sl; sl= sl->next_select())
{
sl->join->result= result;
select_limit_cnt= HA_POS_ERROR;
offset_limit_cnt= 0;
if (!sl->join->procedure &&
result->prepare(sl->join->fields_list, this))
{
DBUG_RETURN(1);
}
sl->join->select_options|= SELECT_DESCRIBE;
sl->join->reinit();
}
}
DBUG_RETURN(0);
}
prepared= 1;
res= 0;
@ -169,8 +190,9 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
{
if (!(tmp_result= union_result= new select_union(0)))
goto err;
union_result->not_describe= 1;
union_result->tmp_table_param.init();
if (describe)
tmp_result= sel_result;
}
else
{
@ -327,11 +349,11 @@ int st_select_lex_unit::exec()
ulonglong add_rows=0;
DBUG_ENTER("st_select_lex_unit::exec");
if (executed && !uncacheable)
if (executed && !uncacheable && !describe)
DBUG_RETURN(0);
executed= 1;
if (uncacheable || !item || !item->assigned())
if (uncacheable || !item || !item->assigned() || describe)
{
if (optimized && item && item->assigned())
{
@ -350,7 +372,7 @@ int st_select_lex_unit::exec()
res= sl->join->reinit();
else
{
if (sl != global_parameters)
if (sl != global_parameters && !describe)
{
offset_limit_cnt= sl->offset_limit;
select_limit_cnt= sl->select_limit+sl->offset_limit;
@ -362,7 +384,7 @@ int st_select_lex_unit::exec()
We can't use LIMIT at this stage if we are using ORDER BY for the
whole query
*/
if (sl->order_list.first)
if (sl->order_list.first || describe)
select_limit_cnt= HA_POS_ERROR;
else
select_limit_cnt= sl->select_limit+sl->offset_limit;