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authorAlexander Barkov <bar@mariadb.org>2017-07-07 12:43:10 +0400
committerAlexander Barkov <bar@mariadb.org>2017-07-07 12:43:10 +0400
commit8b2c7c9444db2369d2ecdaa1f14fbc8826a8fb39 (patch)
tree72fa33f92344a89792845bab9225cef56b4138c4 /sql/sql_select.cc
parent3f327432942ef5db14dd905ffd147f234dc74bfb (diff)
parent3b862aaa10942e7405b90cf80d0c3baca4cda55d (diff)
downloadmariadb-git-8b2c7c9444db2369d2ecdaa1f14fbc8826a8fb39.tar.gz
Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext
Diffstat (limited to 'sql/sql_select.cc')
-rw-r--r--sql/sql_select.cc77
1 files changed, 71 insertions, 6 deletions
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 656dd66506c..29ca0491eba 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1451,6 +1451,7 @@ JOIN::optimize_inner()
if (!select_lex->have_window_funcs())
zero_result_cause= "Select tables optimized away";
tables_list= 0; // All tables resolved
+ select_lex->min_max_opt_list.empty();
const_tables= top_join_tab_count= table_count;
/*
Extract all table-independent conditions and replace the WHERE
@@ -2669,8 +2670,11 @@ bool JOIN::make_aggr_tables_info()
if (sort_table_cond)
{
if (!curr_tab->select)
+ {
if (!(curr_tab->select= new SQL_SELECT))
DBUG_RETURN(true);
+ curr_tab->select->head= curr_tab->table;
+ }
if (!curr_tab->select->cond)
curr_tab->select->cond= sort_table_cond;
else
@@ -5978,7 +5982,7 @@ add_group_and_distinct_keys(JOIN *join, JOIN_TAB *join_tab)
Item_field *cur_item;
key_map possible_keys(0);
- if (join->group_list)
+ if (join->group_list || join->simple_group)
{ /* Collect all query fields referenced in the GROUP clause. */
for (cur_group= join->group_list; cur_group; cur_group= cur_group->next)
(*cur_group->item)->walk(&Item::collect_item_field_processor, 0,
@@ -8374,6 +8378,63 @@ bool JOIN_TAB::hash_join_is_possible()
}
+/**
+ @brief
+ Check whether a KEYUSE can be really used for access this join table
+
+ @param join Join structure with the best join order
+ for which the check is performed
+ @param keyuse Evaluated KEYUSE structure
+
+ @details
+ This function is supposed to be used after the best execution plan have been
+ already chosen and the JOIN_TAB array for the best join order been already set.
+ For a given KEYUSE to access this JOIN_TAB in the best execution plan the
+ function checks whether it really can be used. The function first performs
+ the check with access_from_tables_is_allowed(). If it succeeds it checks
+ whether the keyuse->val does not use some fields of a materialized semijoin
+ nest that cannot be used to build keys to access outer tables.
+ Such KEYUSEs exists for the query like this:
+ select * from ot
+ where ot.c in (select it1.c from it1, it2 where it1.c=f(it2.c))
+ Here we have two KEYUSEs to access table ot: with val=it1.c and val=f(it2.c).
+ However if the subquery was materialized the second KEYUSE cannot be employed
+ to access ot.
+
+ @retval true the given keyuse can be used for ref access of this JOIN_TAB
+ @retval false otherwise
+*/
+
+bool JOIN_TAB::keyuse_is_valid_for_access_in_chosen_plan(JOIN *join,
+ KEYUSE *keyuse)
+{
+ if (!access_from_tables_is_allowed(keyuse->used_tables,
+ join->sjm_lookup_tables))
+ return false;
+ if (join->sjm_scan_tables & table->map)
+ return true;
+ table_map keyuse_sjm_scan_tables= keyuse->used_tables &
+ join->sjm_scan_tables;
+ if (!keyuse_sjm_scan_tables)
+ return true;
+ uint sjm_tab_nr= 0;
+ while (!(keyuse_sjm_scan_tables & table_map(1) << sjm_tab_nr))
+ sjm_tab_nr++;
+ JOIN_TAB *sjm_tab= join->map2table[sjm_tab_nr];
+ TABLE_LIST *emb_sj_nest= sjm_tab->emb_sj_nest;
+ if (!(emb_sj_nest->sj_mat_info && emb_sj_nest->sj_mat_info->is_used &&
+ emb_sj_nest->sj_mat_info->is_sj_scan))
+ return true;
+ st_select_lex *sjm_sel= emb_sj_nest->sj_subq_pred->unit->first_select();
+ for (uint i= 0; i < sjm_sel->item_list.elements; i++)
+ {
+ if (sjm_sel->ref_pointer_array[i] == keyuse->val)
+ return true;
+ }
+ return false;
+}
+
+
static uint
cache_record_length(JOIN *join,uint idx)
{
@@ -8963,6 +9024,7 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
do
{
if (!(~used_tables & keyuse->used_tables) &&
+ join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) &&
are_tables_local(join_tab, keyuse->used_tables))
{
if (first_keyuse)
@@ -8977,6 +9039,8 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
{
if (curr->keypart == keyuse->keypart &&
!(~used_tables & curr->used_tables) &&
+ join_tab->keyuse_is_valid_for_access_in_chosen_plan(join,
+ keyuse) &&
are_tables_local(join_tab, curr->used_tables))
break;
}
@@ -9011,6 +9075,7 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
do
{
if (!(~used_tables & keyuse->used_tables) &&
+ join_tab->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) &&
are_tables_local(join_tab, keyuse->used_tables))
{
bool add_key_part= TRUE;
@@ -9020,7 +9085,9 @@ static bool create_hj_key_for_table(JOIN *join, JOIN_TAB *join_tab,
{
if (curr->keypart == keyuse->keypart &&
!(~used_tables & curr->used_tables) &&
- are_tables_local(join_tab, curr->used_tables))
+ join_tab->keyuse_is_valid_for_access_in_chosen_plan(join,
+ curr) &&
+ are_tables_local(join_tab, curr->used_tables))
{
keyuse->keypart= NO_KEYPART;
add_key_part= FALSE;
@@ -9122,8 +9189,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
do
{
if (!(~used_tables & keyuse->used_tables) &&
- j->access_from_tables_is_allowed(keyuse->used_tables,
- join->sjm_lookup_tables))
+ j->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse))
{
if (are_tables_local(j, keyuse->val->used_tables()))
{
@@ -9193,8 +9259,7 @@ static bool create_ref_for_key(JOIN *join, JOIN_TAB *j,
for (i=0 ; i < keyparts ; keyuse++,i++)
{
while (((~used_tables) & keyuse->used_tables) ||
- !j->access_from_tables_is_allowed(keyuse->used_tables,
- join->sjm_lookup_tables) ||
+ !j->keyuse_is_valid_for_access_in_chosen_plan(join, keyuse) ||
keyuse->keypart == NO_KEYPART ||
(keyuse->keypart !=
(is_hash_join_key_no(key) ?