Adding upstream version 1:10.11.6.upstream/1%10.11.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 557 insertions, 0 deletions

diff --git a/mysql-test/include/index_merge1.inc b/mysql-test/include/index_merge1.inc
new file mode 100644
index 00000000..91609f62
--- /dev/null
+++ b/mysql-test/include/index_merge1.inc
@@ -0,0 +1,557 @@
+# include/index_merge1.inc
+#
+# Index merge tests
+#
+# The variable
+#     $merge_table_support -- 1 storage engine supports merge tables
+#                          -- 0 storage engine does not support merge tables
+# has to be set before sourcing this script.
+#
+# Note: The comments/expectations refer to MyISAM.
+#       They might be not valid for other storage engines.
+#
+# Last update:
+# 2006-08-02 ML test refactored
+#               old name was t/index_merge.test
+#               main code went into include/index_merge1.inc
+#
+--source include/have_sequence.inc
+
+--echo #---------------- Index merge test 1 -------------------------------------------
+
+# Create and fill a table with simple keys
+create table t0
+(
+  key1 int not null,
+  INDEX i1(key1)
+);
+
+insert into t0(key1) select seq from seq_1_to_1024;
+
+alter table t0 add key2 int not null, add index i2(key2);
+alter table t0 add key3 int not null, add index i3(key3);
+alter table t0 add key4 int not null, add index i4(key4);
+alter table t0 add key5 int not null, add index i5(key5);
+alter table t0 add key6 int not null, add index i6(key6);
+alter table t0 add key7 int not null, add index i7(key7);
+alter table t0 add key8 int not null, add index i8(key8);
+
+update t0 set key2=key1,key3=key1,key4=key1,key5=key1,key6=key1,key7=key1,key8=1024-key1;
+analyze table t0;
+
+# 1. One index
+explain select * from t0 where key1 < 3 or key1 > 920 and key1 < 924;
+
+# 2. Simple cases
+explain
+select * from t0 where key1 < 3 or key2 > 920 and key2 < 924;
+select * from t0 where key1 < 3 or key2 > 920 and key2 < 924;
+
+select * from t0 where key1=1022; # MDEV-13535 no-key-read select after keyread
+
+explain select * from t0 where key1 < 3 or key2 <4;
+
+explain
+select * from t0 where (key1 > 30 and key1<35) or (key2 >32 and key2 < 40);
+# Bug#21277: InnoDB, wrong result set, index_merge strategy, second index not evaluated
+select * from t0 where (key1 > 30 and key1<35) or (key2 >32 and key2 < 40);
+
+# 3. Check that index_merge doesn't break "ignore/force/use index"
+explain select * from t0 ignore index (i2) where key1 < 3 or key2 <4;
+explain select * from t0 where (key1 < 3 or key2 <4) and key3 = 50;
+explain select * from t0 use index (i1,i2) where (key1 < 3 or key2 <4) and key3 = 50;
+
+explain select * from t0 where (key1 > 1 or key2  > 2);
+explain select * from t0 force index (i1,i2) where (key1 > 1 or key2  > 2);
+
+
+# 4. Check if conjuncts are grouped by keyuse
+explain
+  select * from t0 where key1<3 or key2<3 or (key1>5 and key1<8) or
+  (key1>10 and key1<12) or (key2>100 and key2<110);
+
+# 5. Check index_merge with conjuncts that are always true/false
+#    verify fallback to "range" if there is only one non-confluent condition
+explain select * from t0 where key2 = 45 or key1 <=> null;
+
+explain select * from t0 where key2 = 45 or key1 is not null;
+explain select * from t0 where key2 = 45 or key1 is null;
+
+#   the last conj. is always false and will be discarded
+explain select * from t0 where key2=10 or key3=3 or key4 <=> null;
+
+#   the last conj. is always true and will cause 'all' scan
+explain select * from t0 where key2=10 or key3=3 or key4 is null;
+
+#   some more complicated cases
+explain select key1 from t0 where (key1 <=> null) or (key2 < 5) or
+                                   (key3=10) or (key4 <=> null);
+explain select key1 from t0 where (key1 <=> null) or (key1 < 5) or
+                                   (key3=10) or (key4 <=> null);
+
+# 6.Several ways to do index_merge, (ignored) index_merge vs. range
+explain select * from t0 where
+  (key1 < 3 or key2 < 3) and (key3 < 4 or key4 < 4) and (key5 < 5 or key6 < 5);
+
+explain
+select * from t0 where (key1 < 3 or key2 < 6) and (key1 < 7 or key3 < 4);
+
+select * from t0 where (key1 < 3 or key2 < 6) and (key1 < 7 or key3 < 4);
+
+explain select * from t0 where
+  (key1 < 3 or key2 < 3) and (key3 < 4 or key4 < 4) and (key5 < 2 or key6 < 2);
+
+#   now index_merge is not used at all when "range" is possible
+explain select * from t0 where
+  (key1 < 3 or key2 < 3) and (key3 < 100);
+
+#   this even can cause "all" scan:
+explain select * from t0 where
+  (key1 < 3 or key2 < 3) and (key3 < 1000);
+
+
+# 7. Complex cases
+#   tree_or(List<SEL_IMERGE>, range SEL_TREE).
+explain select * from t0 where
+    ((key1 < 4 or key2 < 4) and (key2 <5 or key3 < 4))
+  or
+    key2 > 5;
+
+explain select * from t0 where
+    ((key1 < 4 or key2 < 4) and (key2 <5 or key3 < 4))
+  or
+    key1 < 7;
+
+select * from t0 where
+    ((key1 < 4 or key2 < 4) and (key2 <5 or key3 < 4))
+  or
+    key1 < 7;
+
+#   tree_or(List<SEL_IMERGE>, List<SEL_IMERGE>).
+select count(*) from t0 where
+    ((key1 < 4 or key2 < 4) and (key3 <5 or key5 < 4))
+  or
+    ((key5 < 5 or key6 < 6) and (key7 <7 or key8 < 4));
+explain select * from t0 where
+    ((key1 < 4 or key2 < 4) and (key3 <5 or key5 < 4))
+  or
+    ((key5 < 5 or key6 < 6) and (key7 <7 or key8 < 4));
+
+explain select * from t0 where
+    ((key3 <5 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key7 <7 or key8 < 4) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 where
+    ((key3 <5 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key3 <7 or key5 < 2) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 where
+    ((key3 <5 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    (((key3 <7 and key7 < 6) or key5 < 2) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 where
+    ((key3 < 4 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key3 >=5 or key5 < 2) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 force index(i1, i2, i3, i4, i5, i6 ) where
+    ((key3 < 4 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key3 >=5 or key5 < 2) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 force index(i1, i2, i3, i4, i5, i6 ) where
+    ((key3 < 5 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key3 >=5 or key5 < 2) and (key5 < 5 or key6 < 6));
+
+explain select * from t0 force index(i1, i2, i3, i4, i5, i6 ) where
+    ((key3 < 10 or key5 < 4) and (key1 < 4 or key2 < 4))
+  or
+    ((key3 >=5 or key5 < 2) and (key5 < 5 or key6 < 6));
+
+# 8. Verify that "order by" after index merge uses filesort
+select * from t0 where key1 < 5 or key8 < 4 order by key1;
+
+explain
+select * from t0 where key1 < 5 or key8 < 4 order by key1;
+
+# 9. Check that index_merge cost is compared to 'index' where possible
+create table t2 like t0;
+insert into t2 select * from t0;
+
+alter table t2 add index i1_3(key1, key3);
+alter table t2 add index i2_3(key2, key3);
+alter table t2 drop index i1;
+alter table t2 drop index i2;
+alter table t2 add index i321(key3, key2, key1);
+
+#   index_merge vs 'index', index_merge is better.
+explain select key3 from t2 where key1 = 100 or key2 = 100;
+
+#   index_merge vs 'index', 'index' is better.
+explain select key3 from t2 where key1 < 600 or key2 < 600;
+
+#   index_merge vs 'all', index_merge is better.
+explain select key7 from t2 where key1 <100 or key2 < 100;
+
+# 10. Multipart keys.
+create table t4 (
+  key1a int not null,
+  key1b int not null,
+  key2  int not null,
+  key2_1 int not null,
+  key2_2 int not null,
+  key3  int not null,
+  index i1a (key1a, key1b),
+  index i1b (key1b, key1a),
+  index i2_1(key2, key2_1),
+  index i2_2(key2, key2_1)
+);
+
+insert into t4 select seq,seq,seq div 10, seq % 10, seq % 10, seq from seq_1_to_1024;
+
+#   the following will be handled by index_merge:
+select * from t4 where key1a = 3 or key1b = 4;
+explain select * from t4 where key1a = 3 or key1b = 4;
+
+#   and the following will not
+explain select * from t4 where key2 = 1 and (key2_1 = 1 or key3 = 5);
+
+explain select * from t4 where key2 = 1 and (key2_1 = 1 or key2_2 = 5);
+
+explain select * from t4 where key2_1 = 1 or key2_2 = 5;
+
+
+# 11. Multitable selects
+create table t1 like t0;
+insert into t1 select * from t0;
+
+#  index_merge on first table in join
+explain select * from t0 left join t1 on (t0.key1=t1.key1)
+  where t0.key1=3 or t0.key2=4;
+
+select * from t0 left join t1 on (t0.key1=t1.key1)
+  where t0.key1=3 or t0.key2=4;
+
+explain
+select * from t0,t1 where (t0.key1=t1.key1) and ( t0.key1=3 or t0.key2=4);
+
+#  index_merge vs. ref
+explain
+select * from t0,t1 where (t0.key1=t1.key1) and
+  (t0.key1=3 or t0.key2=4) and t1.key1<200;
+
+#  index_merge vs. ref
+explain
+select * from t0,t1 where (t0.key1=t1.key1) and
+  (t0.key1=3 or t0.key2<4) and t1.key1=2;
+
+#  index_merge on second table in join
+explain select * from t0,t1 where t0.key1 = 5 and
+  (t1.key1 = t0.key1 or t1.key8 = t0.key1);
+
+# Fix for bug#1974
+explain select * from t0,t1 where t0.key1 < 3 and
+  (t1.key1 = t0.key1 or t1.key8 = t0.key1);
+
+#  index_merge inside union
+explain select * from t1 where key1=3 or key2=4
+  union select * from t1 where key1<4 or key3=5;
+
+#  index merge in subselect
+set @tmp_optimizer_switch=@@optimizer_switch;
+set optimizer_switch='derived_merge=off,derived_with_keys=off';
+explain select * from (select * from t1 where key1 = 3 or key2 =3) as Z where key8 >5;
+set optimizer_switch=@tmp_optimizer_switch;
+
+# 12. check for long index_merges.
+create table t3 like t0;
+insert into t3 select * from t0;
+alter table t3 add key9 int not null, add index i9(key9);
+alter table t3 add keyA int not null, add index iA(keyA);
+alter table t3 add keyB int not null, add index iB(keyB);
+alter table t3 add keyC int not null, add index iC(keyC);
+update t3 set key9=key1,keyA=key1,keyB=key1,keyC=key1;
+
+explain select * from t3 where
+  key1=1 or key2=2 or key3=3 or key4=4 or
+  key5=5 or key6=6 or key7=7 or key8=8 or
+  key9=9 or keyA=10 or keyB=11 or keyC=12;
+
+select * from t3 where
+  key1=1 or key2=2 or key3=3 or key4=4 or
+  key5=5 or key6=6 or key7=7 or key8=8 or
+  key9=9 or keyA=10 or keyB=11 or keyC=12;
+
+# Test for Bug#3183
+explain select * from t0 where key1 < 3 or key2 < 4;
+# Bug#21277: InnoDB, wrong result set, index_merge strategy, second index not evaluated
+select * from t0 where key1 < 3 or key2 < 4;
+
+update t0 set key8=123 where key1 < 3 or key2 < 4;
+# Bug#21277: InnoDB, wrong result set, index_merge strategy, second index not evaluated
+select * from t0 where key1 < 3 or key2 < 4;
+
+delete from t0 where key1 < 3 or key2 < 4;
+select * from t0 where key1 < 3 or key2 < 4;
+select count(*) from t0;
+
+# Test for BUG#4177
+
+# enable view-protocol after fix MDEV-27871
+--disable_view_protocol
+
+drop table t4;
+create table t4 (a int);
+insert into t4 values (1),(4),(3);
+set @save_join_buffer_size=@@join_buffer_size;
+set join_buffer_size= 4096;
+explain select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
+  where (A.key1 < 500000 or A.key2 < 3)
+  and   (B.key1 < 500000 or B.key2 < 3);
+
+select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
+  where (A.key1 < 500000 or A.key2 < 3)
+  and   (B.key1 < 500000 or B.key2 < 3);
+
+update t0 set key1=1;
+explain select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
+  where (A.key1 = 1 or A.key2 = 1)
+  and   (B.key1 = 1 or B.key2 = 1);
+
+select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
+  where (A.key1 = 1 or A.key2 = 1)
+  and   (B.key1 = 1 or B.key2 = 1);
+
+alter table t0 add filler1 char(200), add filler2 char(200), add filler3 char(200);
+update t0 set key2=1, key3=1, key4=1, key5=1,key6=1,key7=1 where key7 < 500;
+
+# The next query will not use index i7 in intersection if the OS doesn't
+# support file sizes > 2GB. (ha_myisam::ref_length depends on this and index
+# scan cost estimates depend on ha_myisam::ref_length)
+--replace_column 9 #
+--replace_result "4,4,4,4,4,4,4" X "4,4,4,4,4,4" X "i6,i7" "i6,i7?" "i6" "i6,i7?"
+explain select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A straight_join t0 as B
+ where (A.key1 = 1 and A.key2 = 1 and A.key3 = 1 and A.key4=1 and A.key5=1 and A.key6=1 and A.key7 = 1 or A.key8=1)
+  and (B.key1 = 1 and B.key2 = 1 and B.key3 = 1 and B.key4=1 and B.key5=1 and B.key6=1 and B.key7 = 1 or B.key8=1);
+
+select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
+ from t0 as A straight_join t0 as B
+ where (A.key1 = 1 and A.key2 = 1 and A.key3 = 1 and A.key4=1 and A.key5=1 and A.key6=1 and A.key7 = 1 or A.key8=1)
+  and (B.key1 = 1 and B.key2 = 1 and B.key3 = 1 and B.key4=1 and B.key5=1 and B.key6=1 and B.key7 = 1 or B.key8=1);
+
+set join_buffer_size= @save_join_buffer_size;
+# Test for BUG#4177 ends
+
+drop table t0, t1, t2, t3, t4;
+
+--enable_view_protocol
+
+# BUG#16166
+CREATE TABLE t1 (
+  cola char(3) not null, colb char(3) not null,  filler char(200),
+  key(cola), key(colb)
+);
+INSERT INTO t1 VALUES ('foo','bar', 'ZZ'),('fuz','baz', 'ZZ');
+
+--disable_query_log
+let $1=9;
+begin;
+while ($1)
+{
+  eval INSERT INTO t1 SELECT * from t1 WHERE cola = 'foo';
+  dec $1;
+}
+
+let $1=13;
+while ($1)
+{
+  eval INSERT INTO t1 SELECT * from t1 WHERE cola <> 'foo';
+  dec $1;
+}
+commit;
+
+--enable_query_log
+
+OPTIMIZE TABLE t1;
+select count(*) from t1;
+explain select * from t1 WHERE cola = 'foo' AND colb = 'bar';
+explain select * from t1 force index(cola,colb) WHERE cola = 'foo' AND colb = 'bar';
+drop table t1;
+
+if ($merge_table_support)
+{
+#
+# BUG#17314: Index_merge/intersection not chosen by the optimizer for MERGE tables
+#
+create table t1 (
+  a int, b int,
+  filler1 char(200), filler2 char(200),
+  key(a),key(b)
+);
+insert into t1 select @v:= seq % 10, @v, 't1', 'filler2' from seq_1_to_1000;
+
+create table t2 like t1;
+
+create table t3 (
+  a int, b int,
+  filler1 char(200), filler2 char(200),
+  key(a),key(b)
+) engine=merge union=(t1,t2);
+
+--replace_column 9 #
+explain select * from t1 where a=1 and b=1;
+--replace_column 9 #
+explain select * from t3 where a=1 and b=1;
+
+drop table t1, t2, t3;
+}
+
+#
+# BUG#20256 - LOCK WRITE - MyISAM
+#
+--disable_service_connection
+CREATE TABLE t1(a INT);
+INSERT INTO t1 VALUES(1);
+CREATE TABLE t2(a INT, b INT, dummy CHAR(16) DEFAULT '', KEY(a), KEY(b));
+INSERT INTO t2(a,b) VALUES
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
+(1,2);
+LOCK TABLES t1 WRITE, t2 WRITE;
+INSERT INTO t2(a,b) VALUES(1,2);
+SELECT t2.a FROM t1,t2 WHERE t2.b=2 AND t2.a=1;
+UNLOCK TABLES;
+DROP TABLE t1, t2;
+--enable_service_connection
+
+#
+# BUG#29740: HA_KEY_SCAN_NOT_ROR wasn't set for HEAP engine
+# 
+CREATE TABLE `t1` (
+  `a` int(11) DEFAULT NULL,
+  `filler` char(200) DEFAULT NULL,
+  `b` int(11) DEFAULT NULL,
+  KEY `a` (`a`),
+  KEY `b` (`b`)
+) ENGINE=MEMORY DEFAULT CHARSET=latin1;
+
+insert into t1 values
+(0, 'filler', 0), (1, 'filler', 1), (2, 'filler', 2), (3, 'filler', 3), 
+(4, 'filler', 4), (5, 'filler', 5), (6, 'filler', 6), (7, 'filler', 7), 
+(8, 'filler', 8), (9, 'filler', 9), (0, 'filler', 0), (1, 'filler', 1), 
+(2, 'filler', 2), (3, 'filler', 3), (4, 'filler', 4), (5, 'filler', 5), 
+(6, 'filler', 6), (7, 'filler', 7), (8, 'filler', 8), (9, 'filler', 9), 
+(10, 'filler', 10), (11, 'filler', 11), (12, 'filler', 12), (13, 'filler', 13),
+(14, 'filler', 14), (15, 'filler', 15), (16, 'filler', 16), (17, 'filler', 17), 
+(18, 'filler', 18), (19, 'filler', 19), (4, '5      ', 0), (5, '4      ', 0), 
+(4, '4      ', 0), (4, 'qq     ', 5), (5, 'qq     ', 4), (4, 'zz     ', 4);
+
+create table t2(
+  `a` int(11) DEFAULT NULL,
+  `filler` char(200) DEFAULT NULL,
+  `b` int(11) DEFAULT NULL,
+  KEY USING BTREE (`a`),
+  KEY USING BTREE (`b`)
+) ENGINE=MEMORY DEFAULT CHARSET=latin1;
+insert into t2 select * from t1;
+
+
+--echo must use sort-union rather than union:
+--replace_column 9 #
+explain select * from t1 where a=4 or b=4;
+--sorted_result
+select * from t1 where a=4 or b=4;
+--sorted_result
+select * from t1 ignore index(a,b) where a=4 or b=4;
+
+--echo must use union, not sort-union:
+--replace_column 9 #
+explain select * from t2 where a=2 or b=2;
+--sorted_result
+select * from t2 where a=2 or b=2;
+
+drop table t1, t2;
+
+#
+# Bug #37943: Reproducible mysqld crash/sigsegv in sel_trees_can_be_ored
+#
+
+CREATE TABLE t1 (a varchar(8), b set('a','b','c','d','e','f','g','h'),
+                 KEY b(b), KEY a(a));
+INSERT INTO t1 VALUES ('y',''), ('z','');
+
+#should not crash
+SELECT b,a from t1 WHERE (b!='c' AND b!='f' && b!='h') OR 
+  (a='pure-S') OR (a='DE80337a') OR (a='DE80799');
+
+DROP TABLE t1;
+
+--echo #
+--echo # BUG#40974: Incorrect query results when using clause evaluated using range check
+--echo #
+create table t1 (a int);
+insert into t1 values (1),(2);
+create table t2(a int, b int);
+insert into t2 values (1,1), (2, 1000);
+create table t3 (a int, b int, filler char(100), key(a), key(b));
+
+insert into t3 select 1000, 1000,'filler' from seq_1_to_1000;
+insert into t3 values (1,1,'data');
+insert into t3 values (1,1,'data');
+-- echo The plan should be ALL/ALL/ALL(Range checked for each record (index map: 0x3)
+explain select * from t1 
+where exists (select 1 from t2, t3 
+              where t2.a=t1.a and (t3.a=t2.b or t3.b=t2.b or t3.b=t2.b+1));
+
+select * from t1 
+where exists (select 1 from t2, t3 
+              where t2.a=t1.a and (t3.a=t2.b or t3.b=t2.b or t3.b=t2.b+1));
+
+drop table t1, t2, t3;
+
+--echo #
+--echo # BUG#44810: index merge and order by with low sort_buffer_size 
+--echo # crashes server!
+--echo #
+CREATE TABLE t1(a VARCHAR(128),b VARCHAR(128),KEY(A),KEY(B));
+INSERT INTO t1 SELECT REPEAT('a',128),REPEAT('b',128) FROM seq_1_to_64;
+SET SESSION sort_buffer_size=1024*8;
+EXPLAIN 
+SELECT * FROM t1 FORCE INDEX(a,b) WHERE a LIKE 'a%' OR b LIKE 'b%' 
+  ORDER BY a,b;
+# we don't actually care about the result : we're checking if it crashes
+--disable_result_log
+SELECT * FROM t1 FORCE INDEX(a,b) WHERE a LIKE 'a%' OR b LIKE 'b%' 
+  ORDER BY a,b;
+--enable_result_log
+
+SET SESSION sort_buffer_size=DEFAULT;
+DROP TABLE t1;
+
+
+--echo End of 5.0 tests