Backport of commit 904027c820fb344343de6f68a32bcc889f2bd407 to 10.0.21bb-10.0.22-mdev8989

Commit message was:

  Merge branch 'bb-10.1-mdev8989' into 10.1

Some test results are probably not yet updated

3 files changed, 232 insertions, 1 deletions

diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index 294142737d9..2e1475a8bd0 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -2949,3 +2949,148 @@ explain update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 li
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	key1	key1	5	NULL	2	Using where; Using buffer
 drop table t1,t2;
+#
+# MDEV-8989: ORDER BY optimizer ignores equality propagation
+#
+set @tmp_8989=@@optimizer_switch;
+set optimizer_switch='orderby_uses_equalities=on';
+create table t0(a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1(a int);
+insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
+create table t2 (
+pk int primary key, 
+a int, b int, 
+filler char(200), 
+key(a)
+);
+insert into t2 select a, 1000-a, 1000-a, repeat('abc-',50) from t1 where a<200 limit 200;
+create table t3 (
+pk int primary key, 
+a int, b int, 
+filler char(200), 
+key(a)
+);
+insert into t3 select a,      1000-a, 1000-a, repeat('abc-',50) from t1;
+insert into t3 select a+1000, 1000+a, 1000+a, repeat('abc-',50) from t1;
+# The optimizer produces an order of 't2,t3' for this join
+#
+# Case #1 (from the bug report): 
+#  Q1 can take advantage of t2.a to resolve ORDER BY limit w/o sorting
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	index	a	a	5	NULL	5	Using where
+1	SIMPLE	t3	ref	a	a	5	test.t2.a	1	
+# 
+# This is Q2 which used to have "Using temporary; using filesort" but
+#   has the same query plan as Q1:
+# 
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 5;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	index	a	a	5	NULL	5	Using where
+1	SIMPLE	t3	ref	a	a	5	test.t2.a	1	
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 5;
+pk	a	b	pk	a	b
+199	801	801	199	801	801
+198	802	802	198	802	802
+197	803	803	197	803	803
+196	804	804	196	804	804
+195	805	805	195	805	805
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 5;
+pk	a	b	pk	a	b
+199	801	801	199	801	801
+198	802	802	198	802	802
+197	803	803	197	803	803
+196	804	804	196	804	804
+195	805	805	195	805	805
+# 
+# Case #2: here, only "Using temporary" is removed. "Using filesort" remains.
+# 
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 25;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	200	Using where; Using filesort
+1	SIMPLE	t3	ref	a	a	5	test.t2.a	1	
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 25;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	200	Using where; Using filesort
+1	SIMPLE	t3	ref	a	a	5	test.t2.a	1	
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 25;
+pk	a	b	pk	a	b
+199	801	801	199	801	801
+198	802	802	198	802	802
+197	803	803	197	803	803
+196	804	804	196	804	804
+195	805	805	195	805	805
+194	806	806	194	806	806
+193	807	807	193	807	807
+192	808	808	192	808	808
+191	809	809	191	809	809
+190	810	810	190	810	810
+189	811	811	189	811	811
+188	812	812	188	812	812
+187	813	813	187	813	813
+186	814	814	186	814	814
+185	815	815	185	815	815
+184	816	816	184	816	816
+183	817	817	183	817	817
+182	818	818	182	818	818
+181	819	819	181	819	819
+180	820	820	180	820	820
+179	821	821	179	821	821
+178	822	822	178	822	822
+177	823	823	177	823	823
+176	824	824	176	824	824
+175	825	825	175	825	825
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 25;
+pk	a	b	pk	a	b
+199	801	801	199	801	801
+198	802	802	198	802	802
+197	803	803	197	803	803
+196	804	804	196	804	804
+195	805	805	195	805	805
+194	806	806	194	806	806
+193	807	807	193	807	807
+192	808	808	192	808	808
+191	809	809	191	809	809
+190	810	810	190	810	810
+189	811	811	189	811	811
+188	812	812	188	812	812
+187	813	813	187	813	813
+186	814	814	186	814	814
+185	815	815	185	815	815
+184	816	816	184	816	816
+183	817	817	183	817	817
+182	818	818	182	818	818
+181	819	819	181	819	819
+180	820	820	180	820	820
+179	821	821	179	821	821
+178	822	822	178	822	822
+177	823	823	177	823	823
+176	824	824	176	824	824
+175	825	825	175	825	825
+#
+# Case #3: single table access (the code that decides whether we need
+#          "Using temporary" is not invoked)
+#
+explain select * from t3 where b=a order by a limit 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t3	index	NULL	a	5	NULL	10	Using where
+# This must not use filesort. The query plan should be like the query above:
+explain select * from t3 where b=a order by b limit 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t3	index	NULL	a	5	NULL	10	Using where
+drop table t0,t1,t2,t3;
+set @@optimizer_switch=@tmp_8989;
+set optimizer_switch='orderby_uses_equalities=on';
diff --git a/mysql-test/suite/sys_vars/r/optimizer_switch_basic.result b/mysql-test/suite/sys_vars/r/optimizer_switch_basic.result
index 141ab31ea82..a3830d2d16a 100644
--- a/mysql-test/suite/sys_vars/r/optimizer_switch_basic.result
+++ b/mysql-test/suite/sys_vars/r/optimizer_switch_basic.result
@@ -67,4 +67,4 @@ ERROR 42000: Variable 'optimizer_switch' can't be set to the value of 'foobar'
 SET @@global.optimizer_switch = @start_global_value;
 SELECT @@global.optimizer_switch;
 @@global.optimizer_switch
-index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=on
+index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=off,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=off
diff --git a/mysql-test/t/order_by.test b/mysql-test/t/order_by.test
index cf6a4d473c3..84a5b151da4 100644
--- a/mysql-test/t/order_by.test
+++ b/mysql-test/t/order_by.test
@@ -1958,3 +1958,89 @@ select A.a + 10 * B.a + 100 * C.a, 1234 from t2 A, t2 B, t2 C;
 --echo # Should show rows=2, not rows=100
 explain update t1 set key1=key1+1 where key1 between 10 and 110 order by key1 limit 2;
 drop table t1,t2;
+
+--echo #
+--echo # MDEV-8989: ORDER BY optimizer ignores equality propagation
+--echo #
+set @tmp_8989=@@optimizer_switch;
+set optimizer_switch='orderby_uses_equalities=on';
+create table t0(a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t1(a int);
+insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
+
+create table t2 (
+  pk int primary key, 
+  a int, b int, 
+  filler char(200), 
+  key(a)
+);
+insert into t2 select a, 1000-a, 1000-a, repeat('abc-',50) from t1 where a<200 limit 200;
+
+create table t3 (
+  pk int primary key, 
+  a int, b int, 
+  filler char(200), 
+  key(a)
+);
+insert into t3 select a,      1000-a, 1000-a, repeat('abc-',50) from t1;
+insert into t3 select a+1000, 1000+a, 1000+a, repeat('abc-',50) from t1;
+
+--echo # The optimizer produces an order of 't2,t3' for this join
+--echo #
+--echo # Case #1 (from the bug report): 
+--echo #  Q1 can take advantage of t2.a to resolve ORDER BY limit w/o sorting
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 5;
+
+--echo # 
+--echo # This is Q2 which used to have "Using temporary; using filesort" but
+--echo #   has the same query plan as Q1:
+--echo # 
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 5; 
+
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 5;
+
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 5;
+
+
+--echo # 
+--echo # Case #2: here, only "Using temporary" is removed. "Using filesort" remains.
+--echo # 
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 25;
+
+explain
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 25; 
+
+
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t2.a limit 25;
+
+
+select t2.pk,t2.a,t2.b,t3.pk,t3.a,t3.b 
+from t2, t3 where t2.a=t3.a order by t3.a limit 25; 
+
+--echo #
+--echo # Case #3: single table access (the code that decides whether we need
+--echo #          "Using temporary" is not invoked)
+--echo #
+explain select * from t3 where b=a order by a limit 10;
+
+--echo # This must not use filesort. The query plan should be like the query above:
+explain select * from t3 where b=a order by b limit 10;
+drop table t0,t1,t2,t3;
+
+set @@optimizer_switch=@tmp_8989;
+
+set optimizer_switch='orderby_uses_equalities=on';
+
+