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Merge bk-internal.mysql.com:/home/bk/mysql-4.1

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into  mockturtle.local:/home/dlenev/src/mysql-4.1-rt-merge
This commit is contained in:
dlenev@mockturtle.local
2006-10-03 08:19:06 +04:00
parent 5f3cf1eca3 acaa584c55
commit c30b6eafac
4 changed files with 91 additions and 22 deletions
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43
sql/sql_select.cc
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@ -933,17 +933,28 @@ JOIN::optimize()
tmp_table_param.hidden_field_count= (all_fields.elements -
fields_list.elements);
ORDER *tmp_group= ((!simple_group && !procedure &&
!(test_flags & TEST_NO_KEY_GROUP)) ? group_list :
(ORDER*) 0);
/*
Pushing LIMIT to the temporary table creation is not applicable
when there is ORDER BY or GROUP BY or there is no GROUP BY, but
there are aggregate functions, because in all these cases we need
all result rows.
*/
ha_rows tmp_rows_limit= ((order == 0 || skip_sort_order ||
test(select_options & OPTION_BUFFER_RESULT)) &&
!tmp_group &&
!thd->lex->current_select->with_sum_func) ?
select_limit : HA_POS_ERROR;
if (!(exec_tmp_table1 =
create_tmp_table(thd, &tmp_table_param, all_fields,
((!simple_group && !procedure &&
!(test_flags & TEST_NO_KEY_GROUP)) ?
group_list : (ORDER*) 0),
tmp_group,
group_list ? 0 : select_distinct,
group_list && simple_group,
select_options,
(order == 0 || skip_sort_order ||
test(select_options & OPTION_BUFFER_RESULT)) ?
select_limit : HA_POS_ERROR,
tmp_rows_limit,
(char *) "")))
DBUG_RETURN(1);
@ -5567,6 +5578,13 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
thd->variables.max_heap_table_size) :
thd->variables.tmp_table_size)/ table->reclength);
set_if_bigger(table->max_rows,1); // For dummy start options
/*
Push the LIMIT clause to the temporary table creation, so that we
materialize only up to 'rows_limit' records instead of all result records.
*/
set_if_smaller(table->max_rows, rows_limit);
param->end_write_records= rows_limit;
keyinfo=param->keyinfo;
if (group)
@ -5687,19 +5705,6 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
}
}
/*
Push the LIMIT clause to the temporary table creation, so that we
materialize only up to 'rows_limit' records instead of all result records.
This optimization is not applicable when there is GROUP BY or there is
no GROUP BY, but there are aggregate functions, because both must be
computed for all result rows.
*/
if (!group && !thd->lex->current_select->with_sum_func)
{
set_if_smaller(table->max_rows, rows_limit);
param->end_write_records= rows_limit;
}
if (thd->is_fatal_error) // If end of memory
goto err; /* purecov: inspected */
table->db_record_offset=1;