database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

bug#21507 I can't create a unique hash index in NDB: Added possibillity to create hash only indexes with NULL valued attributes, but any NULL valued access will become full table scan with pushed condition on index attribute values

Browse Source
This commit is contained in:
unknown
2006-11-07 16:38:37 +01:00
parent 0c9fc6ba40
commit 807d6c0950
4 changed files with 259 additions and 53 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
mysql-test/r/ndb_index_unique.result
View File

@ -140,7 +140,40 @@ b int unsigned not null,
c int unsigned,
UNIQUE USING HASH (b, c)
) engine=ndbcluster;
ERROR 42000: Column 'c' is used with UNIQUE or INDEX but is not defined as NOT NULL
Warnings:
Warning 1121 Ndb does not support unique index on NULL valued attributes, index access with NULL value will become full table scan
insert t2 values(1,1,NULL),(2,2,2),(3,3,NULL),(4,4,4),(5,5,NULL),(6,6,6),(7,7,NULL),(8,3,NULL),(9,3,NULL);
select * from t2 where c IS NULL order by a;
a b c
1 1 NULL
3 3 NULL
5 5 NULL
7 7 NULL
8 3 NULL
9 3 NULL
select * from t2 where b = 3 AND c IS NULL order by a;
a b c
3 3 NULL
8 3 NULL
9 3 NULL
select * from t2 where (b = 3 OR b = 5) AND c IS NULL order by a;
a b c
3 3 NULL
5 5 NULL
8 3 NULL
9 3 NULL
set @old_ecpd = @@session.engine_condition_pushdown;
set engine_condition_pushdown = true;
explain select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY,b PRIMARY 4 NULL 1 Using where with pushed condition
select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
a b c
3 3 NULL
5 5 NULL
8 3 NULL
set engine_condition_pushdown = @old_ecpd;
drop table t2;
CREATE TABLE t3 (
a int unsigned NOT NULL,
b int unsigned not null,

15
mysql-test/t/ndb_index_unique.test
View File

@ -85,7 +85,6 @@ select * from t2 order by a;
drop table t2;
-- error 1121
CREATE TABLE t2 (
a int unsigned NOT NULL PRIMARY KEY,
b int unsigned not null,
@ -93,6 +92,20 @@ CREATE TABLE t2 (
UNIQUE USING HASH (b, c)
) engine=ndbcluster;
insert t2 values(1,1,NULL),(2,2,2),(3,3,NULL),(4,4,4),(5,5,NULL),(6,6,6),(7,7,NULL),(8,3,NULL),(9,3,NULL);
select * from t2 where c IS NULL order by a;
select * from t2 where b = 3 AND c IS NULL order by a;
select * from t2 where (b = 3 OR b = 5) AND c IS NULL order by a;
set @old_ecpd = @@session.engine_condition_pushdown;
set engine_condition_pushdown = true;
explain select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
select * from t2 where (b = 3 OR b = 5) AND c IS NULL AND a < 9 order by a;
set engine_condition_pushdown = @old_ecpd;
drop table t2;
#
# Show use of PRIMARY KEY USING HASH indexes
#