summaryrefslogtreecommitdiff
path: root/sql/opt_subselect.cc
diff options
context:
space:
mode:
Diffstat (limited to 'sql/opt_subselect.cc')
-rw-r--r--sql/opt_subselect.cc61
1 files changed, 41 insertions, 20 deletions
diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index 1855224440c..3cbde7b4bc8 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -154,9 +154,9 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
!join->having && !select_lex->with_sum_func && // 4
thd->thd_marker.emb_on_expr_nest && // 5
select_lex->outer_select()->join && // 6
- select_lex->master_unit()->first_select()->leaf_tables && // 7
+ select_lex->master_unit()->first_select()->leaf_tables.elements && // 7
in_subs->exec_method == Item_in_subselect::NOT_TRANSFORMED && // 8
- select_lex->outer_select()->leaf_tables && // 9
+ select_lex->outer_select()->leaf_tables.elements && // 9
!((join->select_options | // 10
select_lex->outer_select()->join->select_options) // 10
& SELECT_STRAIGHT_JOIN)) // 10
@@ -212,9 +212,9 @@ int check_and_do_in_subquery_rewrites(JOIN *join)
if (optimizer_flag(thd, OPTIMIZER_SWITCH_MATERIALIZATION) &&
in_subs && // 1
!select_lex->is_part_of_union() && // 2
- select_lex->master_unit()->first_select()->leaf_tables && // 3
+ select_lex->master_unit()->first_select()->leaf_tables.elements && // 3
thd->lex->sql_command == SQLCOM_SELECT && // *
- select_lex->outer_select()->leaf_tables && // 3A
+ select_lex->outer_select()->leaf_tables.elements && // 3A
subquery_types_allow_materialization(in_subs) &&
// psergey-todo: duplicated_subselect_card_check: where it's done?
(in_subs->is_top_level_item() ||
@@ -391,11 +391,26 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
Item_in_subselect **in_subq;
Item_in_subselect **in_subq_end;
THD *thd= join->thd;
+ TABLE_LIST *tbl;
+ List_iterator<TABLE_LIST> ti(join->select_lex->leaf_tables);
DBUG_ENTER("convert_join_subqueries_to_semijoins");
if (join->sj_subselects.elements() == 0)
DBUG_RETURN(FALSE);
+ for (in_subq= join->sj_subselects.front(),
+ in_subq_end= join->sj_subselects.back();
+ in_subq != in_subq_end;
+ in_subq++)
+ {
+ SELECT_LEX *subq_sel= (*in_subq)->get_select_lex();
+ if (subq_sel->handle_derived(thd->lex, DT_OPTIMIZE))
+ DBUG_RETURN(1);
+ if (subq_sel->handle_derived(thd->lex, DT_MERGE))
+ DBUG_RETURN(TRUE);
+ subq_sel->update_used_tables();
+ }
+
/* First, convert child join's subqueries. We proceed bottom-up here */
for (in_subq= join->sj_subselects.front(),
in_subq_end= join->sj_subselects.back();
@@ -422,11 +437,12 @@ bool convert_join_subqueries_to_semijoins(JOIN *join)
// Temporary measure: disable semi-joins when they are together with outer
// joins.
- for (TABLE_LIST *tbl= join->select_lex->leaf_tables; tbl; tbl=tbl->next_leaf)
+ while ((tbl= ti++))
{
TABLE_LIST *embedding= tbl->embedding;
- if (tbl->on_expr || (tbl->embedding && !(embedding->sj_on_expr &&
- !embedding->embedding)))
+ if (tbl->on_expr ||
+ (embedding && embedding->outer_join &&
+ !(embedding->sj_on_expr && !embedding->embedding)))
{
in_subq= join->sj_subselects.front();
arena= thd->activate_stmt_arena_if_needed(&backup);
@@ -737,7 +753,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
st_select_lex *subq_lex= subq_pred->unit->first_select();
nested_join->join_list.empty();
List_iterator_fast<TABLE_LIST> li(subq_lex->top_join_list);
- TABLE_LIST *tl, *last_leaf;
+ TABLE_LIST *tl;
while ((tl= li++))
{
tl->embedding= sj_nest;
@@ -752,17 +768,15 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
NOTE: We actually insert them at the front! That's because the order is
reversed in this list.
*/
- for (tl= parent_lex->leaf_tables; tl->next_leaf; tl= tl->next_leaf) ;
- tl->next_leaf= subq_lex->leaf_tables;
- last_leaf= tl;
+ parent_lex->leaf_tables.concat(&subq_lex->leaf_tables);
/*
Same as above for next_local chain
(a theory: a next_local chain always starts with ::leaf_tables
because view's tables are inserted after the view)
*/
- for (tl= parent_lex->leaf_tables; tl->next_local; tl= tl->next_local) ;
- tl->next_local= subq_lex->leaf_tables;
+ for (tl= parent_lex->leaf_tables.head(); tl->next_local; tl= tl->next_local) ;
+ tl->next_local= subq_lex->leaf_tables.head();
/* A theory: no need to re-connect the next_global chain */
@@ -776,7 +790,8 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
/* n. Adjust the parent_join->tables counter */
uint table_no= parent_join->tables;
/* n. Walk through child's tables and adjust table->map */
- for (tl= subq_lex->leaf_tables; tl; tl= tl->next_leaf, table_no++)
+ List_iterator_fast<TABLE_LIST> si(subq_lex->leaf_tables);
+ while ((tl= si++))
{
tl->table->tablenr= table_no;
tl->table->map= ((table_map)1) << table_no;
@@ -786,6 +801,7 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
emb && emb->select_lex == old_sl;
emb= emb->embedding)
emb->select_lex= parent_join->select_lex;
+ table_no++;
}
parent_join->tables += subq_lex->join->tables;
@@ -872,7 +888,8 @@ static bool convert_subq_to_sj(JOIN *parent_join, Item_in_subselect *subq_pred)
{
/* Inject into the WHERE */
parent_join->conds= and_items(parent_join->conds, sj_nest->sj_on_expr);
- parent_join->conds->fix_fields(parent_join->thd, &parent_join->conds);
+ if (!parent_join->conds->fixed)
+ parent_join->conds->fix_fields(parent_join->thd, &parent_join->conds);
parent_join->select_lex->where= parent_join->conds;
}
@@ -1424,6 +1441,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables,
TABLE_LIST *emb_sj_nest;
POSITION *pos= join->positions + idx;
remaining_tables &= ~new_join_tab->table->map;
+ bool disable_jbuf= join->thd->variables.join_cache_level == 0;
pos->prefix_cost.convert_from_cost(*current_read_time);
pos->prefix_record_count= *current_record_count;
@@ -1593,7 +1611,8 @@ void advance_sj_state(JOIN *join, table_map remaining_tables,
optimize_wo_join_buffering(join, pos->first_loosescan_table, idx,
remaining_tables,
TRUE, //first_alt
- pos->first_loosescan_table + n_tables,
+ disable_jbuf ? join->tables :
+ pos->first_loosescan_table + n_tables,
&reopt_rec_count,
&reopt_cost, &sj_inner_fanout);
/*
@@ -1734,8 +1753,8 @@ void advance_sj_state(JOIN *join, table_map remaining_tables,
/* Need to re-run best-access-path as we prefix_rec_count has changed */
for (i= first_tab + mat_info->tables; i <= idx; i++)
{
- best_access_path(join, join->positions[i].table, rem_tables, i, FALSE,
- prefix_rec_count, &curpos, &dummy);
+ best_access_path(join, join->positions[i].table, rem_tables, i,
+ disable_jbuf, prefix_rec_count, &curpos, &dummy);
prefix_rec_count *= curpos.records_read;
prefix_cost += curpos.read_time;
}
@@ -2031,6 +2050,7 @@ at_sjmat_pos(const JOIN *join, table_map remaining_tables, const JOIN_TAB *tab,
void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
{
uint table_count=join->tables;
+ bool disable_jbuf= join->thd->variables.join_cache_level == 0;
uint tablenr;
table_map remaining_tables= 0;
table_map handled_tabs= 0;
@@ -2092,8 +2112,9 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
join->cur_sj_inner_tables= 0;
for (i= first + sjm->tables; i <= tablenr; i++)
{
- best_access_path(join, join->best_positions[i].table, rem_tables, i, FALSE,
- prefix_rec_count, join->best_positions + i, &dummy);
+ best_access_path(join, join->best_positions[i].table, rem_tables, i,
+ disable_jbuf, prefix_rec_count,
+ join->best_positions + i, &dummy);
prefix_rec_count *= join->best_positions[i].records_read;
rem_tables &= ~join->best_positions[i].table->table->map;
}
View Lorry Controller Status