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WL#2985 "Partition Pruning": post-review fixes: Better comments

This commit is contained in:
sergefp@mysql.com
2005-12-29 09:32:46 +03:00
parent 328f8fa735
commit f2d603c245
4 changed files with 48 additions and 17 deletions

View File

@ -259,3 +259,18 @@ explain partitions select * from t1 where a is not null;
id select_type table partitions type possible_keys key key_len ref rows Extra
1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 2 Using where
drop table t1;
create table t1 (a int not null, b int not null, key(a), key(b))
partition by hash(a) partitions 4;
insert into t1 values (1,1),(2,2),(3,3),(4,4);
explain partitions
select * from t1 X, t1 Y
where X.b = Y.b and (X.a=1 or X.a=2) and (Y.a=2 or Y.a=3);
id select_type table partitions type possible_keys key key_len ref rows Extra
1 SIMPLE X p1,p2 ALL a,b NULL NULL NULL 4 Using where
1 SIMPLE Y p2,p3 ref a,b b 4 test.X.b 2 Using where
explain partitions
select * from t1 X, t1 Y where X.a = Y.a and (X.a=1 or X.a=2);
id select_type table partitions type possible_keys key key_len ref rows Extra
1 SIMPLE X p1,p2 ALL a NULL NULL NULL 4 Using where
1 SIMPLE Y p1,p2 ref a a 4 test.X.a 2
drop table t1;

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@ -230,9 +230,22 @@ create table t1 (a int) partition by hash(a) partitions 2;
insert into t1 values (1),(2);
explain partitions select * from t1 where a is null;
# this selects both
# this uses both partitions
explain partitions select * from t1 where a is not null;
drop table t1;
# Join tests
create table t1 (a int not null, b int not null, key(a), key(b))
partition by hash(a) partitions 4;
insert into t1 values (1,1),(2,2),(3,3),(4,4);
explain partitions
select * from t1 X, t1 Y
where X.b = Y.b and (X.a=1 or X.a=2) and (Y.a=2 or Y.a=3);
explain partitions
select * from t1 X, t1 Y where X.a = Y.a and (X.a=1 or X.a=2);
drop table t1;
# No tests for NULLs in RANGE(monotonic_expr()) - they depend on BUG#15447
# being fixed.