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Merge mysql.com:/home/timka/mysql/src/5.0-virgin

Browse source 
into  mysql.com:/home/timka/mysql/src/5.1-dbg
This commit is contained in:
timour@mysql.com 2005-12-01 12:12:24 +02:00
commit aa864660d7
6 changed files with 112 additions and 12 deletions
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31
mysql-test/r/group_min_max.result
View file

@ -2012,3 +2012,34 @@ explain select distinct f1, f2 from t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL PRIMARY 5 NULL 3 Using index for group-by; Using temporary
drop table t1;
create table t1 (c1 int not null,c2 int not null, primary key(c1,c2));
insert into t1 (c1,c2) values
(10,1),(10,2),(10,3),(20,4),(20,5),(20,6),(30,7),(30,8),(30,9);
select distinct c1, c2 from t1 order by c2;
c1 c2
10 1
10 2
10 3
20 4
20 5
20 6
30 7
30 8
30 9
select c1,min(c2) as c2 from t1 group by c1 order by c2;
c1 c2
10 1
20 4
30 7
select c1,c2 from t1 group by c1,c2 order by c2;
c1 c2
10 1
10 2
10 3
20 4
20 5
20 6
30 7
30 8
30 9
drop table t1;

12
mysql-test/t/group_min_max.test
View file

@ -703,3 +703,15 @@ alter table t1 drop primary key, add primary key (f2, f1);
explain select distinct f1 a, f1 b from t1;
explain select distinct f1, f2 from t1;
drop table t1;
#
# Bug #14920 Ordering aggregated result sets with composite primary keys
# corrupts resultset
#
create table t1 (c1 int not null,c2 int not null, primary key(c1,c2));
insert into t1 (c1,c2) values
(10,1),(10,2),(10,3),(20,4),(20,5),(20,6),(30,7),(30,8),(30,9);
select distinct c1, c2 from t1 order by c2;
select c1,min(c2) as c2 from t1 group by c1 order by c2;
select c1,c2 from t1 group by c1,c2 order by c2;
drop table t1;

1
sql/sql_class.cc
View file

@ -1817,6 +1817,7 @@ void TMP_TABLE_PARAM::init()
group_parts= group_length= group_null_parts= 0;
quick_group= 1;
table_charset= 0;
precomputed_group_by= 0;
}

9
sql/sql_class.h
View file

@ -1833,11 +1833,18 @@ public:
uint convert_blob_length;
CHARSET_INFO *table_charset;
bool schema_table;
/*
True if GROUP BY and its aggregate functions are already computed
by a table access method (e.g. by loose index scan). In this case
query execution should not perform aggregation and should treat
aggregate functions as normal functions.
*/
bool precomputed_group_by;
TMP_TABLE_PARAM()
:copy_field(0), group_parts(0),
group_length(0), group_null_parts(0), convert_blob_length(0),
schema_table(0)
schema_table(0), precomputed_group_by(0)
{}
~TMP_TABLE_PARAM()
{

65
sql/sql_select.cc
View file

@ -1003,6 +1003,20 @@ JOIN::optimize()
}
having= 0;
/*
The loose index scan access method guarantees that all grouping or
duplicate row elimination (for distinct) is already performed
during data retrieval, and that all MIN/MAX functions are already
computed for each group. Thus all MIN/MAX functions should be
treated as regular functions, and there is no need to perform
grouping in the main execution loop.
Notice that currently loose index scan is applicable only for
single table queries, thus it is sufficient to test only the first
join_tab element of the plan for its access method.
*/
if (join_tab->is_using_loose_index_scan())
tmp_table_param.precomputed_group_by= TRUE;
/* Create a tmp table if distinct or if the sort is too complicated */
if (need_tmp)
{
@ -1409,6 +1423,15 @@ JOIN::exec()
else
{
/* group data to new table */
/*
If the access method is loose index scan then all MIN/MAX
functions are precomputed, and should be treated as regular
functions. See extended comment in JOIN::exec.
*/
if (curr_join->join_tab->is_using_loose_index_scan())
curr_join->tmp_table_param.precomputed_group_by= TRUE;
if (!(curr_tmp_table=
exec_tmp_table2= create_tmp_table(thd,
&curr_join->tmp_table_param,
@ -8311,6 +8334,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
TABLE *table;
TABLE_SHARE *share;
uint i,field_count,null_count,null_pack_length;
uint copy_func_count= param->func_count;
uint hidden_null_count, hidden_null_pack_length, hidden_field_count;
uint blob_count,group_null_items, string_count;
uint temp_pool_slot=MY_BIT_NONE;
@ -8374,6 +8398,16 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
field_count=param->field_count+param->func_count+param->sum_func_count;
hidden_field_count=param->hidden_field_count;
/*
When loose index scan is employed as access method, it already
computes all groups and the result of all aggregate functions. We
make space for the items of the aggregate function in the list of
functions TMP_TABLE_PARAM::items_to_copy, so that the values of
these items are stored in the temporary table.
*/
if (param->precomputed_group_by)
copy_func_count+= param->sum_func_count;
init_sql_alloc(&own_root, TABLE_ALLOC_BLOCK_SIZE, 0);
if (!multi_alloc_root(&own_root,
@ -8382,7 +8416,7 @@ create_tmp_table(THD *thd,TMP_TABLE_PARAM *param,List<Item> &fields,
&reg_field, sizeof(Field*) * (field_count+1),
&blob_field, sizeof(uint)*(field_count+1),
&from_field, sizeof(Field*)*field_count,
&copy_func, sizeof(*copy_func)*(param->func_count+1),
&copy_func, sizeof(*copy_func)*(copy_func_count+1),
&param->keyinfo, sizeof(*param->keyinfo),
&key_part_info,
sizeof(*key_part_info)*(param->group_parts+1),
@ -9283,11 +9317,13 @@ bool create_myisam_from_heap(THD *thd, TABLE *table, TMP_TABLE_PARAM *param,
Next_select_func setup_end_select_func(JOIN *join)
{
TABLE *table= join->tmp_table;
TMP_TABLE_PARAM *tmp_tbl= &join->tmp_table_param;
Next_select_func end_select;
/* Set up select_end */
if (table)
{
if (table->group && join->tmp_table_param.sum_func_count)
if (table->group && tmp_tbl->sum_func_count)
{
if (table->s->keys)
{
@ -9300,7 +9336,7 @@ Next_select_func setup_end_select_func(JOIN *join)
end_select=end_unique_update;
}
}
else if (join->sort_and_group)
else if (join->sort_and_group && !tmp_tbl->precomputed_group_by)
{
DBUG_PRINT("info",("Using end_write_group"));
end_select=end_write_group;
@ -9309,19 +9345,27 @@ Next_select_func setup_end_select_func(JOIN *join)
{
DBUG_PRINT("info",("Using end_write"));
end_select=end_write;
if (tmp_tbl->precomputed_group_by)
{
/*
A preceding call to create_tmp_table in the case when loose
index scan is used guarantees that
TMP_TABLE_PARAM::items_to_copy has enough space for the group
by functions. It is OK here to use memcpy since we copy
Item_sum pointers into an array of Item pointers.
*/
memcpy(tmp_tbl->items_to_copy + tmp_tbl->func_count,
join->sum_funcs,
sizeof(Item*)*tmp_tbl->sum_func_count);
tmp_tbl->items_to_copy[tmp_tbl->func_count+tmp_tbl->sum_func_count]= 0;
}
}
}
else
{
/* Test if data is accessed via QUICK_GROUP_MIN_MAX_SELECT. */
bool is_using_quick_group_min_max_select=
(join->join_tab->select && join->join_tab->select->quick &&
(join->join_tab->select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX));
if ((join->sort_and_group ||
(join->procedure && join->procedure->flags & PROC_GROUP)) &&
!is_using_quick_group_min_max_select)
!tmp_tbl->precomputed_group_by)
end_select= end_send_group;
else
end_select= end_send;
@ -10599,7 +10643,6 @@ end_write(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
{
copy_fields(&join->tmp_table_param);
copy_funcs(join->tmp_table_param.items_to_copy);
#ifdef TO_BE_DELETED
if (!table->uniques) // If not unique handling
{

6
sql/sql_select.h
View file

@ -141,6 +141,12 @@ typedef struct st_join_table {
nested_join_map embedding_map;
void cleanup();
inline bool is_using_loose_index_scan()
{
return (select && select->quick &&
(select->quick->get_type() ==
QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX));
}
} JOIN_TAB;
enum_nested_loop_state sub_select_cache(JOIN *join, JOIN_TAB *join_tab, bool