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c3f46e1f26
- Make the code produce correct result: use an array of triggers to turn on/off equalities for each compared column. Also turn on/off optimizations based on those equalities. - Make EXPLAIN output show "Full scan on NULL key" for tables for which we switch between ref/unique_subquery/index_subquery and ALL access. - index_subquery engine now has HAVING clause when it is needed, and it is displayed in EXPLAIN EXTENDED - Fix incorrect presense of "Using index" for index/unique-based subqueries (BUG#22930) // bk trigger note: this commit refers to BUG#24127
61 lines
2.1 KiB
Text
61 lines
2.1 KiB
Text
drop table if exists t1;
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drop table if exists t2;
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create table t1 (p int not null primary key, u int not null, o int not null,
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unique (u), key(o)) engine=ndb;
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create table t2 (p int not null primary key, u int not null, o int not null,
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unique (u), key(o)) engine=ndb;
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insert into t1 values (1,1,1),(2,2,2),(3,3,3);
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insert into t2 values (1,1,1),(2,2,2),(3,3,3), (4,4,4), (5,5,5);
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explain select * from t2 where p NOT IN (select p from t1);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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2 DEPENDENT SUBQUERY t1 unique_subquery PRIMARY PRIMARY 4 func 1
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select * from t2 where p NOT IN (select p from t1) order by p;
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p u o
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4 4 4
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5 5 5
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explain select * from t2 where p NOT IN (select u from t1);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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2 DEPENDENT SUBQUERY t1 unique_subquery u u 4 func 1
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select * from t2 where p NOT IN (select u from t1) order by p;
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p u o
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4 4 4
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5 5 5
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explain select * from t2 where p NOT IN (select o from t1);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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2 DEPENDENT SUBQUERY t1 index_subquery o o 4 func 1
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select * from t2 where p NOT IN (select o from t1) order by p;
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p u o
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4 4 4
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5 5 5
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explain select * from t2 where p NOT IN (select p+0 from t1);
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id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t2 ALL NULL NULL NULL NULL 5 Using where
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2 DEPENDENT SUBQUERY t1 ALL NULL NULL NULL NULL 3 Using where
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select * from t2 where p NOT IN (select p+0 from t1) order by p;
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p u o
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4 4 4
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5 5 5
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drop table t1;
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drop table t2;
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create table t1 (p int not null primary key, u int not null) engine=ndb;
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insert into t1 values (1,1),(2,2),(3,3);
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create table t2 as
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select t1.*
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from t1 as t1, t1 as t2, t1 as t3, t1 as t4, t1 as t5, t1 as t6, t1 as t7, t1 as t8
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where t1.u = t2.u
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and t2.u = t3.u
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and t3.u = t4.u
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and t4.u = t5.u
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and t5.u = t6.u
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and t6.u = t7.u
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and t7.u = t8.u;
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select * from t2 order by 1;
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p u
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1 1
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2 2
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3 3
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drop table t1;
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drop table t2;
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