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Bug #4981: 4.x and 5.x produce non-optimal execution path,

Browse source 
3.23 regression test failure

The member SEL_ARG::min_flag was not initialized, 
due to which the condition for no GEOM_FLAG in function 
key_or did not choose "Range checked for each record" as 
the correct access method.
This commit is contained in:
gkodinov@mysql.com 2006-06-02 12:04:03 +03:00
parent de8a1b4f19
commit b519877c90
3 changed files with 29 additions and 1 deletions
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14
mysql-test/r/select.result
View file

@ -2714,3 +2714,17 @@ select * from t1 where f1 in (select f3 from t2 where (f3,f4)= (select f3,f4 fro
f1 f2
1 1
drop table t1,t2;
CREATE TABLE t1(a int, b int, c int, KEY b(b), KEY c(c));
insert into t1 values (1,0,0),(2,0,0);
CREATE TABLE t2 (a int, b varchar(2), c varchar(2), PRIMARY KEY(a));
insert into t2 values (1,'',''), (2,'','');
CREATE TABLE t3 (a int, b int, PRIMARY KEY (a,b), KEY a (a), KEY b (b));
insert into t3 values (1,1),(1,2);
explain select straight_join DISTINCT t2.a,t2.b, t1.c from t1, t3, t2
where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
t2.b like '%%' order by t2.b limit 0,1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref b,c b 5 const 1 Using where; Using temporary; Using filesort
1 SIMPLE t3 index PRIMARY,a,b PRIMARY 8 NULL 2 Using index
1 SIMPLE t2 ALL PRIMARY NULL NULL NULL 2 Range checked for each record (index map: 0x1)
DROP TABLE t1,t2,t3;

14
mysql-test/t/select.test
View file

@ -2248,4 +2248,18 @@ insert into t2 values(1,1);
select * from t1 where f1 in (select f3 from t2 where (f3,f4)= (select f3,f4 from t2));
drop table t1,t2;
#
# Bug #4981: 4.x and 5.x produce non-optimal execution path, 3.23 regression test failure
#
CREATE TABLE t1(a int, b int, c int, KEY b(b), KEY c(c));
insert into t1 values (1,0,0),(2,0,0);
CREATE TABLE t2 (a int, b varchar(2), c varchar(2), PRIMARY KEY(a));
insert into t2 values (1,'',''), (2,'','');
CREATE TABLE t3 (a int, b int, PRIMARY KEY (a,b), KEY a (a), KEY b (b));
insert into t3 values (1,1),(1,2);
# must have "range checked" for t2
explain select straight_join DISTINCT t2.a,t2.b, t1.c from t1, t3, t2
where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
t2.b like '%%' order by t2.b limit 0,1;
DROP TABLE t1,t2,t3;
# End of 4.1 tests

2
sql/opt_range.cc
View file

@ -64,7 +64,7 @@ public:
uint8 min_flag, uint8 max_flag, uint8 maybe_flag);
SEL_ARG(enum Type type_arg)
:elements(1),use_count(1),left(0),next_key_part(0),color(BLACK),
type(type_arg)
type(type_arg),min_flag(0)
{}
inline bool is_same(SEL_ARG *arg)
{