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Ported WL#3220 to mysql-next-mr.

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This commit is contained in:
Georgi Kodinov
2009-09-28 10:21:25 +03:00
parent b21cd91780
commit 7aa8cd7a11
14 changed files with 1620 additions and 882 deletions
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130
sql/sql_select.cc
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@ -222,6 +222,7 @@ static void update_tmptable_sum_func(Item_sum **func,TABLE *tmp_table);
static void copy_sum_funcs(Item_sum **func_ptr, Item_sum **end);
static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab);
static bool setup_sum_funcs(THD *thd, Item_sum **func_ptr);
static bool prepare_sum_aggregators(Item_sum **func_ptr, bool need_distinct);
static bool init_sum_functions(Item_sum **func, Item_sum **end);
static bool update_sum_func(Item_sum **func);
static void select_describe(JOIN *join, bool need_tmp_table,bool need_order,
@ -1232,7 +1233,11 @@ JOIN::optimize()
if (test_if_subpart(group_list, order) ||
(!group_list && tmp_table_param.sum_func_count))
{
order=0;
if (is_indexed_agg_distinct(this, NULL))
sort_and_group= 0;
}
// Can't use sort on head table if using row cache
if (full_join)
@ -1410,8 +1415,16 @@ JOIN::optimize()
single table queries, thus it is sufficient to test only the first
join_tab element of the plan for its access method.
*/
bool need_distinct= TRUE;
if (join_tab->is_using_loose_index_scan())
{
tmp_table_param.precomputed_group_by= TRUE;
if (join_tab->is_using_agg_loose_index_scan())
{
need_distinct= FALSE;
tmp_table_param.precomputed_group_by= FALSE;
}
}
/* Create a tmp table if distinct or if the sort is too complicated */
if (need_tmp)
@ -1472,6 +1485,7 @@ JOIN::optimize()
HA_POS_ERROR, HA_POS_ERROR, FALSE) ||
alloc_group_fields(this, group_list) ||
make_sum_func_list(all_fields, fields_list, 1) ||
prepare_sum_aggregators(sum_funcs, need_distinct) ||
setup_sum_funcs(thd, sum_funcs))
{
DBUG_RETURN(1);
@ -1481,6 +1495,7 @@ JOIN::optimize()
else
{
if (make_sum_func_list(all_fields, fields_list, 0) ||
prepare_sum_aggregators(sum_funcs, need_distinct) ||
setup_sum_funcs(thd, sum_funcs))
{
DBUG_RETURN(1);
@ -1953,7 +1968,9 @@ JOIN::exec()
}
}
if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
1, TRUE))
1, TRUE) ||
prepare_sum_aggregators(curr_join->sum_funcs,
!curr_join->join_tab->is_using_agg_loose_index_scan()))
DBUG_VOID_RETURN;
curr_join->group_list= 0;
if (!curr_join->sort_and_group &&
@ -2056,6 +2073,8 @@ JOIN::exec()
if (curr_join->make_sum_func_list(*curr_all_fields, *curr_fields_list,
1, TRUE) ||
prepare_sum_aggregators (curr_join->sum_funcs, !curr_join->join_tab ||
!curr_join->join_tab->is_using_agg_loose_index_scan()) ||
setup_sum_funcs(curr_join->thd, curr_join->sum_funcs) ||
thd->is_fatal_error)
DBUG_VOID_RETURN;
@ -3937,6 +3956,82 @@ static void optimize_keyuse(JOIN *join, DYNAMIC_ARRAY *keyuse_array)
}
/**
Check for the presence of AGGFN(DISTINCT a) queries that may be subject
to loose index scan.
Check if the query is a subject to AGGFN(DISTINCT) using loose index scan
(QUICK_GROUP_MIN_MAX_SELECT).
Optionally (if out_args is supplied) will push the arguments of
AGGFN(DISTINCT) to the list
@param join the join to check
@param[out] out_args list of aggregate function arguments
@return does the query qualify for indexed AGGFN(DISTINCT)
@retval true it does
@retval false AGGFN(DISTINCT) must apply distinct in it.
*/
bool
is_indexed_agg_distinct(JOIN *join, List<Item_field> *out_args)
{
Item_sum **sum_item_ptr;
bool result= false;
if (join->tables != 1 || /* reference more than 1 table */
join->select_distinct || /* or a DISTINCT */
join->select_lex->olap == ROLLUP_TYPE) /* Check (B3) for ROLLUP */
return false;
if (join->make_sum_func_list(join->all_fields, join->fields_list, 1))
return false;
for (sum_item_ptr= join->sum_funcs; *sum_item_ptr; sum_item_ptr++)
{
Item_sum *sum_item= *sum_item_ptr;
Item *expr;
/* aggregate is not AGGFN(DISTINCT) or more than 1 argument to it */
switch (sum_item->sum_func())
{
case Item_sum::MIN_FUNC:
case Item_sum::MAX_FUNC:
continue;
case Item_sum::COUNT_DISTINCT_FUNC:
break;
case Item_sum::AVG_DISTINCT_FUNC:
case Item_sum::SUM_DISTINCT_FUNC:
if (sum_item->get_arg_count() == 1)
break;
/* fall through */
default: return false;
}
/*
We arrive here for every COUNT(DISTINCT),AVG(DISTINCT) or SUM(DISTINCT).
Collect the arguments of the aggregate functions to a list.
We don't worry about duplicates as these will be sorted out later in
get_best_group_min_max
*/
for (uint i= 0; i < sum_item->get_arg_count(); i++)
{
expr= sum_item->get_arg(i);
/* The AGGFN(DISTINCT) arg is not an attribute? */
if (expr->real_item()->type() != Item::FIELD_ITEM)
return false;
/*
If we came to this point the AGGFN(DISTINCT) loose index scan
optimization is applicable
*/
if (out_args)
out_args->push_back((Item_field *) expr);
result= true;
}
}
return result;
}
/**
Discover the indexes that can be used for GROUP BY or DISTINCT queries.
@ -3979,6 +4074,10 @@ add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab)
item->walk(&Item::collect_item_field_processor, 0,
(uchar*) &indexed_fields);
}
else if (is_indexed_agg_distinct(join, &indexed_fields))
{
join->sort_and_group= 1;
}
else
return;
@ -10377,6 +10476,7 @@ TABLE *create_virtual_tmp_table(THD *thd, List<Create_field> &field_list)
bzero(share, sizeof(*share));
table->field= field;
table->s= share;
table->temp_pool_slot= MY_BIT_NONE;
share->blob_field= blob_field;
share->fields= field_count;
share->blob_ptr_size= portable_sizeof_char_ptr;
@ -14532,7 +14632,7 @@ setup_new_fields(THD *thd, List<Item> &fields,
optimize away 'order by'.
*/
static ORDER *
ORDER *
create_distinct_group(THD *thd, Item **ref_pointer_array,
ORDER *order_list, List<Item> &fields,
List<Item> &all_fields,
@ -15334,7 +15434,22 @@ static bool setup_sum_funcs(THD *thd, Item_sum **func_ptr)
DBUG_ENTER("setup_sum_funcs");
while ((func= *(func_ptr++)))
{
if (func->setup(thd))
if (func->aggregator_setup(thd))
DBUG_RETURN(TRUE);
}
DBUG_RETURN(FALSE);
}
static bool prepare_sum_aggregators(Item_sum **func_ptr, bool need_distinct)
{
Item_sum *func;
DBUG_ENTER("setup_sum_funcs");
while ((func= *(func_ptr++)))
{
if (func->set_aggregator(need_distinct && func->with_distinct ?
Aggregator::DISTINCT_AGGREGATOR :
Aggregator::SIMPLE_AGGREGATOR))
DBUG_RETURN(TRUE);
}
DBUG_RETURN(FALSE);
@ -15384,7 +15499,7 @@ init_sum_functions(Item_sum **func_ptr, Item_sum **end_ptr)
/* If rollup, calculate the upper sum levels */
for ( ; *func_ptr ; func_ptr++)
{
if ((*func_ptr)->add())
if ((*func_ptr)->aggregator_add())
return 1;
}
return 0;
@ -15396,7 +15511,7 @@ update_sum_func(Item_sum **func_ptr)
{
Item_sum *func;
for (; (func= (Item_sum*) *func_ptr) ; func_ptr++)
if (func->add())
if (func->aggregator_add())
return 1;
return 0;
}
@ -16313,7 +16428,12 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
if (key_read)
{
if (quick_type == QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX)
{
QUICK_GROUP_MIN_MAX_SELECT *qgs=
(QUICK_GROUP_MIN_MAX_SELECT *) tab->select->quick;
extra.append(STRING_WITH_LEN("; Using index for group-by"));
qgs->append_loose_scan_type(&extra);
}
else
extra.append(STRING_WITH_LEN("; Using index"));
}