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Merge willster.(none):/home/stewart/Documents/MySQL/4.1/ndb

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into  willster.(none):/home/stewart/Documents/MySQL/4.1/bug19914-mk2


sql/ha_ndbcluster.cc:
  Auto merged
sql/ha_ndbcluster.h:
  Auto merged
sql/sql_select.cc:
  Auto merged
This commit is contained in:
unknown
2006-09-20 17:09:53 +10:00
parent e34496e5d8 ec2512cf18
commit d4d3dcacaa
89 changed files with 1405 additions and 503 deletions
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98
sql/sql_select.cc
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@@ -650,6 +650,36 @@ JOIN::optimize()
if (!order && org_order)
skip_sort_order= 1;
}
/*
Check if we can optimize away GROUP BY/DISTINCT.
We can do that if there are no aggregate functions and the
fields in DISTINCT clause (if present) and/or columns in GROUP BY
(if present) contain direct references to all key parts of
an unique index (in whatever order).
Note that the unique keys for DISTINCT and GROUP BY should not
be the same (as long as they are unique).
The FROM clause must contain a single non-constant table.
*/
if (tables - const_tables == 1 && (group_list || select_distinct) &&
!tmp_table_param.sum_func_count)
{
if (group_list &&
list_contains_unique_index(join_tab[const_tables].table,
find_field_in_order_list,
(void *) group_list))
{
group_list= 0;
group= 0;
}
if (select_distinct &&
list_contains_unique_index(join_tab[const_tables].table,
find_field_in_item_list,
(void *) &fields_list))
{
select_distinct= 0;
}
}
if (group_list || tmp_table_param.sum_func_count)
{
if (! hidden_group_fields && rollup.state == ROLLUP::STATE_NONE)
@@ -719,36 +749,6 @@ JOIN::optimize()
if (old_group_list && !group_list)
select_distinct= 0;
}
/*
Check if we can optimize away GROUP BY/DISTINCT.
We can do that if there are no aggregate functions and the
fields in DISTINCT clause (if present) and/or columns in GROUP BY
(if present) contain direct references to all key parts of
an unique index (in whatever order).
Note that the unique keys for DISTINCT and GROUP BY should not
be the same (as long as they are unique).
The FROM clause must contain a single non-constant table.
*/
if (tables - const_tables == 1 && (group_list || select_distinct) &&
!tmp_table_param.sum_func_count)
{
if (group_list &&
list_contains_unique_index(join_tab[const_tables].table,
find_field_in_order_list,
(void *) group_list))
{
group_list= 0;
group= 0;
}
if (select_distinct &&
list_contains_unique_index(join_tab[const_tables].table,
find_field_in_item_list,
(void *) &fields_list))
{
select_distinct= 0;
}
}
if (!group_list && group)
{
order=0; // The output has only one row
@@ -4551,6 +4551,8 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
left_item->collation.collation == value->collation.collation))
{
Item *tmp=value->new_item();
tmp->collation.set(right_item->collation);
if (tmp)
{
thd->change_item_tree(args + 1, tmp);
@@ -4572,6 +4574,8 @@ change_cond_ref_to_const(THD *thd, I_List<COND_CMP> *save_list,
right_item->collation.collation == value->collation.collation))
{
Item *tmp=value->new_item();
tmp->collation.set(left_item->collation);
if (tmp)
{
thd->change_item_tree(args, tmp);
@@ -5574,10 +5578,11 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
keyinfo->key_length=0;
keyinfo->rec_per_key=0;
keyinfo->algorithm= HA_KEY_ALG_UNDEF;
for (; group ; group=group->next,key_part_info++)
ORDER *cur_group= group;
for (; cur_group ; cur_group= cur_group->next, key_part_info++)
{
Field *field=(*group->item)->get_tmp_table_field();
bool maybe_null=(*group->item)->maybe_null;
Field *field=(*cur_group->item)->get_tmp_table_field();
bool maybe_null=(*cur_group->item)->maybe_null;
key_part_info->null_bit=0;
key_part_info->field= field;
key_part_info->offset= field->offset();
@@ -5589,8 +5594,8 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
0 : FIELDFLAG_BINARY;
if (!using_unique_constraint)
{
group->buff=(char*) group_buff;
if (!(group->field=field->new_field(thd->mem_root,table)))
cur_group->buff=(char*) group_buff;
if (!(cur_group->field=field->new_field(thd->mem_root,table)))
goto err; /* purecov: inspected */
if (maybe_null)
{
@@ -5604,21 +5609,16 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
key_part_info->null_bit=field->null_bit;
key_part_info->null_offset= (uint) (field->null_ptr -
(uchar*) table->record[0]);
group->field->move_field((char*) ++group->buff);
cur_group->field->move_field((char*) ++cur_group->buff);
group_buff++;
}
else
group->field->move_field((char*) group_buff);
cur_group->field->move_field((char*) group_buff);
group_buff+= key_part_info->length;
}
keyinfo->key_length+= key_part_info->length;
}
}
else
{
set_if_smaller(table->max_rows, rows_limit);
param->end_write_records= rows_limit;
}
if (distinct && field_count != param->hidden_field_count)
{
@@ -5681,6 +5681,20 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
0 : FIELDFLAG_BINARY;
}
}
/*
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;