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Merge remote-tracking branch '5.5' into 10.0

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Vicențiu Ciorbaru
2017-06-20 12:31:17 +03:00
parent 5e4f4ec821 ded614d7db
commit 8baf9b0c46
20 changed files with 623 additions and 45 deletions
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75
sql/sql_select.cc
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@ -1305,6 +1305,7 @@ TODO: make view to decide if it is possible to write to WHERE directly or make S
DBUG_PRINT("info",("Select tables optimized away"));
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
@ -2942,8 +2943,11 @@ void JOIN::exec_inner()
if (sort_table_cond)
{
if (!curr_table->select)
{
if (!(curr_table->select= new SQL_SELECT))
DBUG_VOID_RETURN;
curr_table->select->head= curr_table->table;
}
if (!curr_table->select->cond)
curr_table->select->cond= sort_table_cond;
else
@ -8076,6 +8080,63 @@ 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)
{
@ -8623,6 +8684,7 @@ 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)
@ -8637,6 +8699,8 @@ 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;
}
@ -8671,6 +8735,7 @@ 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;
@ -8680,7 +8745,9 @@ 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;
@ -8782,8 +8849,7 @@ 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()))
{
@ -8853,8 +8919,7 @@ 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) ?