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Commit 6edc0225 authored by Oleg Smirnov's avatar Oleg Smirnov
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MDEV-33281 Make BNL() hint work for join_cache_level=0 

join_cache_level=0 disables join cache buffers, but the hint
BNL() now allows to employ BNL(H) buffers for particular tables
or query blocks.
parent dd8934bd
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Showing with 452 additions and 100 deletions
mysql-test/main/opt_hints.result
View file @ 6edc0225
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mysql-test/main/opt_hints.test
View file @ 6edc0225
......@@ -148,9 +148,9 @@ EXPLAIN EXTENDED SELECT * FROM
WHERE t4.y = 8 AND t5.x BETWEEN 7 AND t4.y+0) AS TD;
--echo # BKA & NO_BKA hint testing
set optimizer_switch=default;
set optimizer_switch='mrr=on,mrr_cost_based=off';
set join_cache_level=6;
set optimizer_switch = DEFAULT;
set optimizer_switch = 'mrr=on,mrr_cost_based=off';
set join_cache_level = 8;
CREATE TABLE t10(a INT);
INSERT INTO t10 VALUES (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
......@@ -359,7 +359,9 @@ DEALLOCATE PREPARE stmt1;
DROP TABLE t1, t2, t3, t10, t11, t12, t13;
--echo # BNL & NO_BNL hint testing
--echo #
--echo # BNL and NO_BNL hint testing
--echo #
set optimizer_switch=default;
......@@ -387,16 +389,27 @@ EXPLAIN EXTENDED SELECT /*+ NO_BNL() */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ NO_BNL(t2, t3) */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ NO_BNL(t1, t3) */t1.* FROM t1,t2,t3;
--echo # MariaDB does not have optimizer_switch='block_nested_loop=off'
--echo # as MySQL does, so in fact we cannot disable BNL join. The cases below
--echo # test the BNL() hint, although it does not affect the execution plan
--echo # Make sure query results are the same for any hints combination
--sorted_result
SELECT * FROM t1,t2,t3;
--sorted_result
SELECT /*+ NO_BNL(t1, t2) */* FROM t1,t2,t3;
--sorted_result
SELECT /*+ NO_BNL(t1, t3) */* FROM t1,t2,t3;
--sorted_result
SELECT /*+ NO_BNL(t2, t3) */* FROM t1,t2,t3;
--echo # BNL() overrides current join_cache_level setting
set join_cache_level = 0;
EXPLAIN EXTENDED SELECT t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL() */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL(t2, t3) */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL(t1, t2) */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL(t1, t3) */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL(t2, t3) */t1.* FROM t1,t2,t3;
EXPLAIN EXTENDED SELECT /*+ BNL(t2) BNL(t3) */t1.* FROM t1,t2,t3;
DROP TABLE t1, t2, t3;
set join_cache_level = 8;
--echo # BNL in subquery
set optimizer_switch = DEFAULT;
......@@ -408,34 +421,141 @@ INSERT INTO t2 VALUES (2), (3), (4), (5);
INSERT INTO t3 VALUES (10,3), (20,4), (30,5);
ANALYZE TABLE t1, t2, t3;
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL() */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t1, t2) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(@subq1) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) */ * FROM t1 JOIN t2 ON t1.a = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL() */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t1, t2) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t4@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t3@subq1,t4@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(@subq1 t3, t4) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) NO_BNL(t3, t4) */ t3.b
FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--echo # Make sure query results are the same for any hints combination
# --sorted_result
SELECT * FROM t1 JOIN t2 ON t1.a = t2.a WHERE
t2.a IN (SELECT t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
# --sorted_result
SELECT /*+ QB_NAME(q) */ * FROM t1 JOIN t2 ON t1.a = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL() */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL(t1, t2) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL(@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL(t4@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL(t3@subq1,t4@subq1) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) NO_BNL(@subq1 t3, t4) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.a = t4.b);
--sorted_result
SELECT /*+ QB_NAME(q) */ *
FROM t1 JOIN t2 ON t1.a = t2.a
WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) NO_BNL(t3, t4) */ t3.b
FROM t3 JOIN t1 t4 ON t3.a = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t4@subq1) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(t3@subq1,t4@subq1) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
DROP TABLE t1, t2, t3, t4;
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) NO_BNL(@subq1 t3, t4) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
--echo #
--echo # BNL() and NO_BNL() for LEFT JOINs
--echo #
EXPLAIN EXTENDED SELECT /*+ QB_NAME(q) */ * FROM t1 JOIN t2 ON t1.b = t2.a WHERE
t2.a IN (SELECT /*+ QB_NAME(subq1) NO_BNL(t3, t4) */ t3.b FROM t3 JOIN t1 t4 ON t3.b = t4.b);
CREATE TABLE t1 (a int);
CREATE TABLE t2 (a int);
CREATE TABLE t3 (a int);
CREATE TABLE t4 (a int);
INSERT INTO t1 VALUES (null), (2), (null), (1);
set join_cache_level = 8;
--echo # Two join buffers are employed by default (without hints):
EXPLAIN SELECT t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.a) ON 0
WHERE t1.a OR t3.a;
--echo # Disabling either of join buffers disables another one automatically due
--echo # to join buffer employment rules:
EXPLAIN SELECT /*+ NO_BNL(t2) */ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.a) ON 0
WHERE t1.a OR t3.a;
EXPLAIN SELECT /*+ NO_BNL(t3) */ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON t2.a) ON 0
WHERE t1.a OR t3.a;
--echo # Three join buffers are employed here by default (without hints):
EXPLAIN SELECT t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
--echo # Disabling either of join buffers disables others automatically due
--echo # to join buffer employment rules:
EXPLAIN SELECT /*+ NO_BNL(t2)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
EXPLAIN SELECT /*+ NO_BNL(t3)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
EXPLAIN SELECT /*+ NO_BNL(t4)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
set join_cache_level=0;
--echo # It is not allowed to enable join buffers on some subset of inner tables
--echo # of an outer join. Either all tables should use join buffers or none:
EXPLAIN SELECT /*+ BNL(t2)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
EXPLAIN SELECT /*+ BNL(t2, t3)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
EXPLAIN SELECT /*+ BNL(t2, t3, t4)*/ t1.a
FROM t1 LEFT JOIN (t2 LEFT JOIN (t3 LEFT JOIN t4 ON 1) ON t2.a) ON 0
WHERE t1.a OR t4.a;
DROP TABLE t1,t2,t3,t4;
DROP TABLE t1, t2, t3, t4;
--echo # MRR & NO_MRR hint testing
set optimizer_switch=default;
set join_cache_level = 8;
CREATE TABLE t1
(
......@@ -750,4 +870,8 @@ SELECT
/*+ ? bad syntax */ 1;
DROP TABLE t1;
set optimizer_switch=default;
set optimizer_switch = DEFAULT;
set join_cache_level = DEFAULT;
--echo #
--echo # End of 11.7 tests
--echo #
sql/sql_select.cc
View file @ 6edc0225
......@@ -15143,12 +15143,19 @@ uint check_join_cache_usage(JOIN_TAB *tab,
if (tab->no_forced_join_cache || (no_bnl_cache && no_bka_cache))
goto no_join_cache;
if (cache_level == 0 && hint_table_state_or_fallback(join->thd,
tab->tab_list->table,
BNL_HINT_ENUM, false))
{
cache_level= 4; // BNL() hint present, raise join_cache_level to BNLH
}
/*
Don't use join cache if @@join_cache_level==0 or this table is the first
one join suborder (either at top level or inside a bush)
*/
if (cache_level == 0 || !prev_tab)
return 0;
goto no_join_cache;
if (force_unlinked_cache && (cache_level%2 == 0))
cache_level--;
......@@ -15227,6 +15234,12 @@ uint check_join_cache_usage(JOIN_TAB *tab,
if (tab->loosescan_match_tab || tab->bush_children)
goto no_join_cache;
/*
An inner table of an outer join nest must not use join buffering if
the first inner table of that outer join nest does not use join buffering
or if the tables in the embedding outer join nest do not use join buffering.
Also see revise_cache_usage()
*/
for (JOIN_TAB *first_inner= tab->first_inner; first_inner;
first_inner= first_inner->first_upper)
{
......@@ -15302,6 +15315,8 @@ uint check_join_cache_usage(JOIN_TAB *tab,
tab->is_ref_for_hash_join() ||
((flags & HA_MRR_NO_ASSOCIATION) && cache_level <=6))
{
if (no_bnl_cache)
goto no_join_cache;
if (!tab->hash_join_is_possible() ||
tab->make_scan_filter())
goto no_join_cache;
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