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MDEV-7317: Make an index ignorable to the optimizer

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This feature adds the functionality of ignorability for indexes.
Indexes are not ignored be default.

To control index ignorability explicitly for a new index,
use IGNORE or NOT IGNORE as part of the index definition for
CREATE TABLE, CREATE INDEX, or ALTER TABLE.

Primary keys (explicit or implicit) cannot be made ignorable.

The table INFORMATION_SCHEMA.STATISTICS get a new column named IGNORED that
would store whether an index needs to be ignored or not.
This commit is contained in:
Varun Gupta
2021-02-25 19:59:51 +05:30
parent 71d30d01aa
commit f691d9865b
108 changed files with 2541 additions and 1422 deletions
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4
mysql-test/suite/heap/heap.result
View File

@ -3,8 +3,8 @@ create table t1 (a int not null,b int not null, primary key (a)) engine=heap com
insert into t1 values(1,1),(2,2),(3,3),(4,4);
delete from t1 where a=1 or a=0;
show keys from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 0 PRIMARY 1 a NULL 3 NULL NULL HASH
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 a NULL 3 NULL NULL HASH NO
select * from t1;
a b
2 2

4
mysql-test/suite/heap/heap_btree.result
View File

@ -3,8 +3,8 @@ create table t1 (a int not null,b int not null, primary key using BTREE (a)) eng
insert into t1 values(1,1),(2,2),(3,3),(4,4);
delete from t1 where a=1 or a=0;
show keys from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 0 PRIMARY 1 a A NULL NULL NULL BTREE
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 a A NULL NULL NULL BTREE NO
select * from t1;
a b
2 2

32
mysql-test/suite/heap/heap_hash.result
View File

@ -3,8 +3,8 @@ create table t1 (a int not null,b int not null, primary key using HASH (a)) engi
insert into t1 values(1,1),(2,2),(3,3),(4,4);
delete from t1 where a=1 or a=0;
show keys from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 0 PRIMARY 1 a NULL 3 NULL NULL HASH
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 a NULL 3 NULL NULL HASH NO
select * from t1;
a b
2 2
@ -327,15 +327,15 @@ explain select * from t1 ignore index (btree_idx) where name='matt';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref heap_idx heap_idx 22 const 7 Using where
show index from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 0 PRIMARY 1 id NULL 91 NULL NULL HASH
t1 1 heap_idx 1 name NULL 13 NULL NULL HASH
t1 1 btree_idx 1 name A NULL NULL NULL BTREE
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 id NULL 91 NULL NULL HASH NO
t1 1 heap_idx 1 name NULL 13 NULL NULL HASH NO
t1 1 btree_idx 1 name A NULL NULL NULL BTREE NO
show index from t1;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t1 0 PRIMARY 1 id NULL 91 NULL NULL HASH
t1 1 heap_idx 1 name NULL 13 NULL NULL HASH
t1 1 btree_idx 1 name A NULL NULL NULL BTREE
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t1 0 PRIMARY 1 id NULL 91 NULL NULL HASH NO
t1 1 heap_idx 1 name NULL 13 NULL NULL HASH NO
t1 1 btree_idx 1 name A NULL NULL NULL BTREE NO
create table t3
(
a varchar(20) not null,
@ -344,13 +344,13 @@ key (a,b)
) engine=heap;
insert into t3 select name, name from t1;
show index from t3;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t3 1 a 1 a NULL NULL NULL NULL HASH
t3 1 a 2 b NULL 13 NULL NULL HASH
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t3 1 a 1 a NULL NULL NULL NULL HASH NO
t3 1 a 2 b NULL 13 NULL NULL HASH NO
show index from t3;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t3 1 a 1 a NULL NULL NULL NULL HASH
t3 1 a 2 b NULL 13 NULL NULL HASH
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment Ignored
t3 1 a 1 a NULL NULL NULL NULL HASH NO
t3 1 a 2 b NULL 13 NULL NULL HASH NO
explain select * from t1 ignore key(btree_idx), t3 where t1.name='matt' and t3.a = concat('',t1.name) and t3.b=t1.name;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref heap_idx heap_idx 22 const 7 Using where