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MDEV-32113: utf8mb3_key_col=utf8mb4_value cannot be used for ref

Browse source 
(Variant#3: Allow cross-charset comparisons, use a special
CHARSET_INFO to create lookup keys. Review input addressed.)

Equalities that compare utf8mb{3,4}_general_ci strings, like:

  WHERE ... utf8mb3_key_col=utf8mb4_value    (MB3-4-CMP)

can now be used to construct ref[const] access and also participate
in multiple-equalities.
This means that utf8mb3_key_col can be used for key-lookups when
compared with an utf8mb4 constant, field or expression using '=' or
'<=>' comparison operators.

This is controlled by optimizer_switch='cset_narrowing=on', which is
OFF by default.

IMPLEMENTATION
Item value comparison in (MB3-4-CMP) is done using utf8mb4_general_ci.
This is valid as any utf8mb3 value is also an utf8mb4 value.

When making index lookup value for utf8mb3_key_col, we do "Charset
Narrowing": characters that are in the Basic Multilingual Plane (=BMP) are
copied as-is, as they can be represented in utf8mb3. Characters that are
outside the BMP cannot be represented in utf8mb3 and are replaced
with U+FFFD, the "Replacement Character".

In utf8mb4_general_ci, the Replacement Character compares as equal to any
character that's not in BMP. Because of this, the constructed lookup value
will find all index records that would be considered equal by the original
condition (MB3-4-CMP).

Approved-by: Monty <monty@mariadb.org>
This commit is contained in:
Sergei Petrunia 2023-09-19 18:22:49 +03:00
parent 6a674c3142
commit 4941ac9192
23 changed files with 1001 additions and 39 deletions

3
include/m_ctype.h
View file

@ -1711,6 +1711,9 @@ my_well_formed_length(CHARSET_INFO *cs, const char *b, const char *e,
#include "t_ctype.h"
#endif
int my_wc_mb_utf8mb4_bmp_only(CHARSET_INFO *cs, my_wc_t wc, uchar *r,
uchar *e);
#ifdef __cplusplus
}
#endif

1
libmysqld/CMakeLists.txt
View file

@ -50,6 +50,7 @@ ENDIF()
SET(SQL_EMBEDDED_SOURCES emb_qcache.cc libmysqld.c lib_sql.cc
libmysql.c ../sql-common/errmsg.c
../sql-common/client.c
../sql/cset_narrowing.cc
../sql-common/my_user.c ../sql-common/pack.c
../sql-common/client_plugin.c
../sql/password.c ../sql/discover.cc ../sql/derror.cc

470
mysql-test/main/cset_narrowing.result Normal file
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@ -0,0 +1,470 @@
set
@tmp_csetn_os= @@optimizer_switch,
optimizer_switch='cset_narrowing=on';
set names utf8mb4;
create table t1 (
mb3name varchar(32),
mb3 varchar(32) collate utf8mb3_general_ci,
key(mb3)
);
insert into t1 select seq, seq from seq_1_to_10000;
insert into t1 values ('mb3-question-mark', '?');
insert into t1 values ('mb3-replacement-char', _utf8mb3 0xEFBFBD);
create table t10 (
pk int auto_increment primary key,
mb4name varchar(32),
mb4 varchar(32) character set utf8mb4 collate utf8mb4_general_ci
);
insert into t10 (mb4name, mb4) values
('mb4-question-mark','?'),
('mb4-replacement-char', _utf8mb4 0xEFBFBD),
('mb4-smiley', _utf8mb4 0xF09F988A),
('1', '1');
analyze table t1,t10 persistent for all;
Table Op Msg_type Msg_text
test.t1 analyze status Engine-independent statistics collected
test.t1 analyze status OK
test.t10 analyze status Engine-independent statistics collected
test.t10 analyze status OK
#
# Check that constants are already handled: the following should use
# ref/range, because constants are converted into utf8mb3.
#
select collation('abc');
collation('abc')
utf8mb4_general_ci
explain select * from t1 force index (mb3) where t1.mb3='abc';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref mb3 mb3 99 const 1 Using index condition
explain select * from t1 force index (mb3) where t1.mb3 in ('abc','cde','xyz');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range mb3 mb3 99 NULL 3 Using index condition
explain select * from t1 force index (mb3) where t1.mb3 between 'abc' and 'acc';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range mb3 mb3 99 NULL 1 Using index condition
explain select * from t1 force index (mb3) where t1.mb3 <'000';
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range mb3 mb3 99 NULL 1 Using index condition
# If a constant can't be represented in utf8mb3, an error is produced:
explain select * from t1 force index (mb3) where t1.mb3='😊';
ERROR HY000: Illegal mix of collations (utf8mb3_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='
#
# Check ref access on mb3_field=mb4_field
#
explain format=json
select * from t10,t1 where t10.mb4=t1.mb3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t10.mb4 is not null"
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"ref": ["test.t10.mb4"],
"rows": 1,
"filtered": 100,
"index_condition": "t1.mb3 = t10.mb4"
}
}
}
select * from t10,t1 where t10.mb4=t1.mb3;
pk mb4name mb4 mb3name mb3
1 mb4-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09>
4 1 1 1 1
select * from t10,t1 use index() where t10.mb4=t1.mb3;
pk mb4name mb4 mb3name mb3
4 1 1 1 1
1 mb4-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09>
explain format=json
select * from t10,t1 where t10.mb4<=>t1.mb3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 100
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"ref": ["test.t10.mb4"],
"rows": 1,
"filtered": 100,
"index_condition": "t10.mb4 <=> t1.mb3"
}
}
}
select * from t10,t1 where t10.mb4<=>t1.mb3;
pk mb4name mb4 mb3name mb3
1 mb4-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09>
4 1 1 1 1
set statement optimizer_switch='cset_narrowing=off', join_cache_level=0 for
explain format=json
select * from t10,t1 where t10.mb4=t1.mb3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 100
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 10002,
"filtered": 100,
"attached_condition": "t10.mb4 = convert(t1.mb3 using utf8mb4)"
}
}
}
#
# Check ref access on mb3_field=mb4_expr
#
explain format=json
select * from t10,t1 where t1.mb3=concat('',t10.mb4);
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 100
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"ref": ["func"],
"rows": 1,
"filtered": 100,
"index_condition": "t1.mb3 = concat('',t10.mb4)"
}
}
}
select * from t10,t1 where t1.mb3=concat('',t10.mb4);
pk mb4name mb4 mb3name mb3
1 mb4-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09>
4 1 1 1 1
select * from t10,t1 use index() where t1.mb3=concat('',t10.mb4);
pk mb4name mb4 mb3name mb3
4 1 1 1 1
1 mb4-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09>
# Check that ref optimizer gets the right constant.
# We need a const table for that, because key=const is handled by
# coercing the constant.
#
# So, we take the smiley:
select * from t10 where t10.pk=3;
pk mb4name mb4
3 mb4-smiley 😊
set optimizer_trace=1;
# And see that we've got the Replacement Character in the ranges:
explain
select * from t10, t1 where t10.mb4=t1.mb3 and t10.pk=3;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t10 const PRIMARY PRIMARY 4 const 1
1 SIMPLE t1 ref mb3 mb3 99 const 3 Using index condition
select
json_detailed(json_extract(trace, '$**.range_scan_alternatives')) as JS
from
information_schema.optimizer_trace;
JS
[
[
{
"index": "mb3",
"ranges":
["(<28>) <= (mb3) <= (<28>)"],
"rowid_ordered": true,
"using_mrr": false,
"index_only": false,
"rows": 3,
"cost": 3.760377105,
"chosen": true
}
]
]
select * from t10, t1 where t10.mb4=t1.mb3 and t10.pk=3;
pk mb4name mb4 mb3name mb3
3 mb4-smiley 😊 mb3-replacement-char <09>
#
# Will range optimizer handle t1.mb3>t10.mb4? No...
#
explain format=json
select * from t10, t1 where (t1.mb3=t10.mb4 or t1.mb3='hello') and t10.pk=3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "const",
"possible_keys": ["PRIMARY"],
"key": "PRIMARY",
"key_length": "4",
"used_key_parts": ["pk"],
"ref": ["const"],
"rows": 1,
"filtered": 100
},
"table": {
"table_name": "t1",
"access_type": "range",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"rows": 4,
"filtered": 100,
"index_condition": "t1.mb3 = '????' or t1.mb3 = 'hello'"
}
}
}
explain format=json
select * from t10, t1 where t1.mb3>t10.mb4 and t10.pk=3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "const",
"possible_keys": ["PRIMARY"],
"key": "PRIMARY",
"key_length": "4",
"used_key_parts": ["pk"],
"ref": ["const"],
"rows": 1,
"filtered": 100
},
"table": {
"table_name": "t1",
"access_type": "ALL",
"rows": 10002,
"filtered": 100,
"attached_condition": "convert(t1.mb3 using utf8mb4) > '????'"
}
}
}
# For comparison, it will handle it when collations match:
create table t2 (
mb4name varchar(32),
mb4 varchar(32) collate utf8mb4_general_ci,
key(mb4)
);
insert into t2 select * from t1;
explain format=json
select * from t10, t2 where t2.mb4>t10.mb4 and t10.pk=3;
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "const",
"possible_keys": ["PRIMARY"],
"key": "PRIMARY",
"key_length": "4",
"used_key_parts": ["pk"],
"ref": ["const"],
"rows": 1,
"filtered": 100
},
"table": {
"table_name": "t2",
"access_type": "range",
"possible_keys": ["mb4"],
"key": "mb4",
"key_length": "131",
"used_key_parts": ["mb4"],
"rows": 3,
"filtered": 100,
"index_condition": "t2.mb4 > '????'"
}
}
}
#
# Check multiple equalities
#
# - ref acccess lookup keys do use equality substitution,
# - concat() arguments don't
explain format=json
select straight_join * from t10,t1 force index(mb3),t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 100,
"attached_condition": "t10.mb4 is not null and t10.mb4 is not null"
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"ref": ["test.t10.mb4"],
"rows": 1,
"filtered": 100,
"index_condition": "t1.mb3 = t10.mb4"
},
"table": {
"table_name": "t2",
"access_type": "ref",
"possible_keys": ["mb4"],
"key": "mb4",
"key_length": "131",
"used_key_parts": ["mb4"],
"ref": ["test.t10.mb4"],
"rows": 1,
"filtered": 100,
"index_condition": "concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe'"
}
}
}
select json_detailed(json_extract(trace, '$**.condition_processing')) as JS
from information_schema.optimizer_trace;
JS
[
{
"condition": "WHERE",
"original_condition": "t1.mb3 = t2.mb4 and t2.mb4 = t10.mb4 and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe'",
"steps":
[
{
"transformation": "equality_propagation",
"resulting_condition": "concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
},
{
"transformation": "constant_propagation",
"resulting_condition": "concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
},
{
"transformation": "trivial_condition_removal",
"resulting_condition": "concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
}
]
}
]
select straight_join * from t10,t1 force index(mb3),t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
pk mb4name mb4 mb3name mb3 mb4name mb4
1 mb4-question-mark ? mb3-question-mark ? mb3-question-mark ?
2 mb4-replacement-char <09> mb3-replacement-char <09> mb3-replacement-char <09>
3 mb4-smiley 😊 mb3-replacement-char <09> mb3-replacement-char <09>
4 1 1 1 1 1 1
# Equality substitution doesn't happen for constants, for both narrowing
# and non-narrowing comparisons:
explain format=json
select * from t10,t1,t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and t10.mb4='hello' and
concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
EXPLAIN
{
"query_block": {
"select_id": 1,
"table": {
"table_name": "t10",
"access_type": "ALL",
"rows": 4,
"filtered": 0.78125,
"attached_condition": "t10.mb4 = 'hello'"
},
"table": {
"table_name": "t1",
"access_type": "ref",
"possible_keys": ["mb3"],
"key": "mb3",
"key_length": "99",
"used_key_parts": ["mb3"],
"ref": ["const"],
"rows": 1,
"filtered": 100,
"index_condition": "t1.mb3 = t10.mb4"
},
"table": {
"table_name": "t2",
"access_type": "ref",
"possible_keys": ["mb4"],
"key": "mb4",
"key_length": "131",
"used_key_parts": ["mb4"],
"ref": ["const"],
"rows": 1,
"filtered": 100,
"index_condition": "t2.mb4 = t10.mb4 and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe'"
}
}
}
select json_detailed(json_extract(trace, '$**.condition_processing')) as JS
from information_schema.optimizer_trace;
JS
[
{
"condition": "WHERE",
"original_condition": "t1.mb3 = t2.mb4 and t2.mb4 = t10.mb4 and t10.mb4 = 'hello' and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe'",
"steps":
[
{
"transformation": "equality_propagation",
"resulting_condition": "t10.mb4 = 'hello' and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
},
{
"transformation": "constant_propagation",
"resulting_condition": "t10.mb4 = 'hello' and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
},
{
"transformation": "trivial_condition_removal",
"resulting_condition": "t10.mb4 = 'hello' and concat(convert(t1.mb3 using utf8mb4),t2.mb4,t10.mb4) <> 'Bebebe' and multiple equal(t1.mb3, t2.mb4, t10.mb4)"
}
]
}
]
drop table t2;
drop table t1, t10;
set optimizer_switch=@tmp_csetn_os;

150
mysql-test/main/cset_narrowing.test Normal file
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@ -0,0 +1,150 @@
#
# Test character set narrowing
#
--source include/have_utf8mb4.inc
--source include/have_sequence.inc
--source include/not_embedded.inc
set
@tmp_csetn_os= @@optimizer_switch,
optimizer_switch='cset_narrowing=on';
set names utf8mb4;
create table t1 (
mb3name varchar(32),
mb3 varchar(32) collate utf8mb3_general_ci,
key(mb3)
);
insert into t1 select seq, seq from seq_1_to_10000;
insert into t1 values ('mb3-question-mark', '?');
insert into t1 values ('mb3-replacement-char', _utf8mb3 0xEFBFBD);
create table t10 (
pk int auto_increment primary key,
mb4name varchar(32),
mb4 varchar(32) character set utf8mb4 collate utf8mb4_general_ci
);
insert into t10 (mb4name, mb4) values
('mb4-question-mark','?'),
('mb4-replacement-char', _utf8mb4 0xEFBFBD),
('mb4-smiley', _utf8mb4 0xF09F988A),
('1', '1');
analyze table t1,t10 persistent for all;
--echo #
--echo # Check that constants are already handled: the following should use
--echo # ref/range, because constants are converted into utf8mb3.
--echo #
select collation('abc');
explain select * from t1 force index (mb3) where t1.mb3='abc';
explain select * from t1 force index (mb3) where t1.mb3 in ('abc','cde','xyz');
explain select * from t1 force index (mb3) where t1.mb3 between 'abc' and 'acc';
explain select * from t1 force index (mb3) where t1.mb3 <'000';
--echo # If a constant can't be represented in utf8mb3, an error is produced:
--error ER_CANT_AGGREGATE_2COLLATIONS
explain select * from t1 force index (mb3) where t1.mb3='😊';
--echo #
--echo # Check ref access on mb3_field=mb4_field
--echo #
explain format=json
select * from t10,t1 where t10.mb4=t1.mb3;
select * from t10,t1 where t10.mb4=t1.mb3;
select * from t10,t1 use index() where t10.mb4=t1.mb3;
explain format=json
select * from t10,t1 where t10.mb4<=>t1.mb3;
select * from t10,t1 where t10.mb4<=>t1.mb3;
set statement optimizer_switch='cset_narrowing=off', join_cache_level=0 for
explain format=json
select * from t10,t1 where t10.mb4=t1.mb3;
--echo #
--echo # Check ref access on mb3_field=mb4_expr
--echo #
explain format=json
select * from t10,t1 where t1.mb3=concat('',t10.mb4);
select * from t10,t1 where t1.mb3=concat('',t10.mb4);
select * from t10,t1 use index() where t1.mb3=concat('',t10.mb4);
--echo # Check that ref optimizer gets the right constant.
--echo # We need a const table for that, because key=const is handled by
--echo # coercing the constant.
--echo #
--echo # So, we take the smiley:
select * from t10 where t10.pk=3;
set optimizer_trace=1;
--echo # And see that we've got the Replacement Character in the ranges:
explain
select * from t10, t1 where t10.mb4=t1.mb3 and t10.pk=3;
select
json_detailed(json_extract(trace, '$**.range_scan_alternatives')) as JS
from
information_schema.optimizer_trace;
select * from t10, t1 where t10.mb4=t1.mb3 and t10.pk=3;
--echo #
--echo # Will range optimizer handle t1.mb3>t10.mb4? No...
--echo #
explain format=json
select * from t10, t1 where (t1.mb3=t10.mb4 or t1.mb3='hello') and t10.pk=3;
explain format=json
select * from t10, t1 where t1.mb3>t10.mb4 and t10.pk=3;
--echo # For comparison, it will handle it when collations match:
create table t2 (
mb4name varchar(32),
mb4 varchar(32) collate utf8mb4_general_ci,
key(mb4)
);
insert into t2 select * from t1;
explain format=json
select * from t10, t2 where t2.mb4>t10.mb4 and t10.pk=3;
--echo #
--echo # Check multiple equalities
--echo #
--echo # - ref acccess lookup keys do use equality substitution,
--echo # - concat() arguments don't
explain format=json
select straight_join * from t10,t1 force index(mb3),t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
select json_detailed(json_extract(trace, '$**.condition_processing')) as JS
from information_schema.optimizer_trace;
select straight_join * from t10,t1 force index(mb3),t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
--echo # Equality substitution doesn't happen for constants, for both narrowing
--echo # and non-narrowing comparisons:
explain format=json
select * from t10,t1,t2
where
t1.mb3=t2.mb4 and t2.mb4=t10.mb4 and t10.mb4='hello' and
concat(t1.mb3, t2.mb4, t10.mb4)<>'Bebebe';
select json_detailed(json_extract(trace, '$**.condition_processing')) as JS
from information_schema.optimizer_trace;
drop table t2;
drop table t1, t10;
set optimizer_switch=@tmp_csetn_os;

2
mysql-test/main/mysqld--help.result
View file

@ -755,7 +755,7 @@ The following specify which files/extra groups are read (specified before remain
condition_pushdown_for_derived, split_materialized,
condition_pushdown_for_subquery, rowid_filter,
condition_pushdown_from_having, not_null_range_scan,
hash_join_cardinality
hash_join_cardinality, cset_narrowing
--optimizer-trace=name
Controls tracing of the Optimizer:
optimizer_trace=option=val[,option=val...], where option

2
mysql-test/main/mysqltest_tracking_info.result
View file

@ -38,7 +38,7 @@ SET @@session.session_track_system_variables='optimizer_switch';
set optimizer_switch='index_merge=off,index_merge_union=off,index_merge_sort_union=off,index_merge_intersection=off,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=on,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off';
-- Tracker : SESSION_TRACK_SYSTEM_VARIABLES
-- optimizer_switch
-- index_merge=off,index_merge_union=off,index_merge_sort_union=off,index_merge_intersection=off,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=on,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
-- index_merge=off,index_merge_union=off,index_merge_sort_union=off,index_merge_intersection=off,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=on,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
Warnings:
Warning 1681 'engine_condition_pushdown=on' is deprecated and will be removed in a future release

32
mysql-test/suite/sys_vars/r/optimizer_switch_basic.result
View file

@ -1,60 +1,60 @@
set @@global.optimizer_switch=@@optimizer_switch;
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
show global variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
show session variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
optimizer_switch index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select * from information_schema.global_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select * from information_schema.session_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off
OPTIMIZER_SWITCH index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
set global optimizer_switch=4101;
set session optimizer_switch=2058;
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
set global optimizer_switch="index_merge_sort_union=on";
set session optimizer_switch="index_merge=off";
select @@global.optimizer_switch;
@@global.optimizer_switch
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
show global variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
optimizer_switch index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
show session variables like 'optimizer_switch';
Variable_name Value
optimizer_switch index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
optimizer_switch index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select * from information_schema.global_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
OPTIMIZER_SWITCH index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
select * from information_schema.session_variables where variable_name='optimizer_switch';
VARIABLE_NAME VARIABLE_VALUE
OPTIMIZER_SWITCH index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
OPTIMIZER_SWITCH index_merge=off,index_merge_union=on,index_merge_sort_union=off,index_merge_intersection=on,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=on,in_to_exists=off,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
set session optimizer_switch="default";
select @@session.optimizer_switch;
@@session.optimizer_switch
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off
index_merge=on,index_merge_union=off,index_merge_sort_union=on,index_merge_intersection=off,index_merge_sort_intersection=off,engine_condition_pushdown=off,index_condition_pushdown=off,derived_merge=off,derived_with_keys=off,firstmatch=off,loosescan=off,materialization=off,in_to_exists=on,semijoin=off,partial_match_rowid_merge=off,partial_match_table_scan=off,subquery_cache=off,mrr=off,mrr_cost_based=off,mrr_sort_keys=off,outer_join_with_cache=off,semijoin_with_cache=off,join_cache_incremental=off,join_cache_hashed=off,join_cache_bka=off,optimize_join_buffer_size=off,table_elimination=off,extended_keys=off,exists_to_in=off,orderby_uses_equalities=off,condition_pushdown_for_derived=off,split_materialized=off,condition_pushdown_for_subquery=off,rowid_filter=off,condition_pushdown_from_having=off,not_null_range_scan=off,hash_join_cardinality=off,cset_narrowing=off
set optimizer_switch = replace(@@optimizer_switch, '=off', '=on');
Warnings:
Warning 1681 'engine_condition_pushdown=on' is deprecated and will be removed in a future release
select @@optimizer_switch;
@@optimizer_switch
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=on,hash_join_cardinality=on
index_merge=on,index_merge_union=on,index_merge_sort_union=on,index_merge_intersection=on,index_merge_sort_intersection=on,engine_condition_pushdown=on,index_condition_pushdown=on,derived_merge=on,derived_with_keys=on,firstmatch=on,loosescan=on,materialization=on,in_to_exists=on,semijoin=on,partial_match_rowid_merge=on,partial_match_table_scan=on,subquery_cache=on,mrr=on,mrr_cost_based=on,mrr_sort_keys=on,outer_join_with_cache=on,semijoin_with_cache=on,join_cache_incremental=on,join_cache_hashed=on,join_cache_bka=on,optimize_join_buffer_size=on,table_elimination=on,extended_keys=on,exists_to_in=on,orderby_uses_equalities=on,condition_pushdown_for_derived=on,split_materialized=on,condition_pushdown_for_subquery=on,rowid_filter=on,condition_pushdown_from_having=on,not_null_range_scan=on,hash_join_cardinality=on,cset_narrowing=on
set global optimizer_switch=1.1;
ERROR 42000: Incorrect argument type to variable 'optimizer_switch'
set global optimizer_switch=1e1;

2
mysql-test/suite/sys_vars/r/sysvars_server_embedded.result
View file

@ -2329,7 +2329,7 @@ VARIABLE_COMMENT Fine-tune the optimizer behavior
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST index_merge,index_merge_union,index_merge_sort_union,index_merge_intersection,index_merge_sort_intersection,engine_condition_pushdown,index_condition_pushdown,derived_merge,derived_with_keys,firstmatch,loosescan,materialization,in_to_exists,semijoin,partial_match_rowid_merge,partial_match_table_scan,subquery_cache,mrr,mrr_cost_based,mrr_sort_keys,outer_join_with_cache,semijoin_with_cache,join_cache_incremental,join_cache_hashed,join_cache_bka,optimize_join_buffer_size,table_elimination,extended_keys,exists_to_in,orderby_uses_equalities,condition_pushdown_for_derived,split_materialized,condition_pushdown_for_subquery,rowid_filter,condition_pushdown_from_having,not_null_range_scan,hash_join_cardinality,default
ENUM_VALUE_LIST index_merge,index_merge_union,index_merge_sort_union,index_merge_intersection,index_merge_sort_intersection,engine_condition_pushdown,index_condition_pushdown,derived_merge,derived_with_keys,firstmatch,loosescan,materialization,in_to_exists,semijoin,partial_match_rowid_merge,partial_match_table_scan,subquery_cache,mrr,mrr_cost_based,mrr_sort_keys,outer_join_with_cache,semijoin_with_cache,join_cache_incremental,join_cache_hashed,join_cache_bka,optimize_join_buffer_size,table_elimination,extended_keys,exists_to_in,orderby_uses_equalities,condition_pushdown_for_derived,split_materialized,condition_pushdown_for_subquery,rowid_filter,condition_pushdown_from_having,not_null_range_scan,hash_join_cardinality,cset_narrowing,default
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME OPTIMIZER_TRACE

2
mysql-test/suite/sys_vars/r/sysvars_server_notembedded.result
View file

@ -2489,7 +2489,7 @@ VARIABLE_COMMENT Fine-tune the optimizer behavior
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST index_merge,index_merge_union,index_merge_sort_union,index_merge_intersection,index_merge_sort_intersection,engine_condition_pushdown,index_condition_pushdown,derived_merge,derived_with_keys,firstmatch,loosescan,materialization,in_to_exists,semijoin,partial_match_rowid_merge,partial_match_table_scan,subquery_cache,mrr,mrr_cost_based,mrr_sort_keys,outer_join_with_cache,semijoin_with_cache,join_cache_incremental,join_cache_hashed,join_cache_bka,optimize_join_buffer_size,table_elimination,extended_keys,exists_to_in,orderby_uses_equalities,condition_pushdown_for_derived,split_materialized,condition_pushdown_for_subquery,rowid_filter,condition_pushdown_from_having,not_null_range_scan,hash_join_cardinality,default
ENUM_VALUE_LIST index_merge,index_merge_union,index_merge_sort_union,index_merge_intersection,index_merge_sort_intersection,engine_condition_pushdown,index_condition_pushdown,derived_merge,derived_with_keys,firstmatch,loosescan,materialization,in_to_exists,semijoin,partial_match_rowid_merge,partial_match_table_scan,subquery_cache,mrr,mrr_cost_based,mrr_sort_keys,outer_join_with_cache,semijoin_with_cache,join_cache_incremental,join_cache_hashed,join_cache_bka,optimize_join_buffer_size,table_elimination,extended_keys,exists_to_in,orderby_uses_equalities,condition_pushdown_for_derived,split_materialized,condition_pushdown_for_subquery,rowid_filter,condition_pushdown_from_having,not_null_range_scan,hash_join_cardinality,cset_narrowing,default
READ_ONLY NO
COMMAND_LINE_ARGUMENT REQUIRED
VARIABLE_NAME OPTIMIZER_TRACE

4
sql/CMakeLists.txt
View file

@ -90,7 +90,9 @@ ENDIF()
SET (SQL_SOURCE
${CMAKE_CURRENT_BINARY_DIR}/yy_mariadb.cc
${CMAKE_CURRENT_BINARY_DIR}/yy_oracle.cc
../sql-common/client.c compat56.cc derror.cc des_key_file.cc
../sql-common/client.c
cset_narrowing.cc
compat56.cc derror.cc des_key_file.cc
discover.cc ../sql-common/errmsg.c
field.cc field_conv.cc field_comp.cc
filesort_utils.cc

35
sql/cset_narrowing.cc Normal file
View file

@ -0,0 +1,35 @@
/*
Copyright (c) 2023, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#include "mariadb.h"
#include "sql_priv.h"
#include "sql_select.h"
Charset_utf8narrow utf8mb3_from_mb4;
bool Utf8_narrow::should_do_narrowing(const THD *thd,
CHARSET_INFO *field_cset,
CHARSET_INFO *value_cset)
{
return optimizer_flag(thd, OPTIMIZER_SWITCH_CSET_NARROWING) &&
field_cset == &my_charset_utf8mb3_general_ci &&
value_cset == &my_charset_utf8mb4_general_ci;
}

143
sql/cset_narrowing.h Normal file
View file

@ -0,0 +1,143 @@
/*
Copyright (c) 2023, MariaDB Corporation.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
#ifndef CSET_NARROWING_H_INCLUDED
#define CSET_NARROWING_H_INCLUDED
/*
A singleton class to provide "utf8mb3_from_mb4.charset()".
This is a variant of utf8mb3_general_ci that one can use when they have data
in MB4 and want to make index lookup keys in MB3.
*/
extern
class Charset_utf8narrow
{
struct my_charset_handler_st cset_handler;
struct charset_info_st cset;
public:
Charset_utf8narrow() :
cset_handler(*my_charset_utf8mb3_general_ci.cset),
cset(my_charset_utf8mb3_general_ci) /* Copy the CHARSET_INFO structure */
{
/* Insert our function wc_mb */
cset_handler.wc_mb= my_wc_mb_utf8mb4_bmp_only;
cset.cset=&cset_handler;
/* Charsets are compared by their name, so assign a different name */
LEX_CSTRING tmp= {STRING_WITH_LEN("utf8_mb4_to_mb3")};
cset.cs_name= tmp;
}
CHARSET_INFO *charset() { return &cset; }
} utf8mb3_from_mb4;
/*
A class to temporary change a field that uses utf8mb3_general_ci to enable
correct lookup key construction from string value in utf8mb4_general_ci
Intended usage:
// can do this in advance:
bool do_narrowing= Utf8_narrow::should_do_narrowing(field, value_cset);
...
// This sets the field to do narrowing if necessary:
Utf8_narrow narrow(field, do_narrowing);
// write to 'field' here
// item->save_in_field(field) or something else
// Stop doing narrowing
narrow.stop();
*/
class Utf8_narrow
{
Field *field;
DTCollation save_collation;
public:
static bool should_do_narrowing(const THD *thd, CHARSET_INFO *field_cset,
CHARSET_INFO *value_cset);
static bool should_do_narrowing(const Field *field, CHARSET_INFO *value_cset)
{
CHARSET_INFO *field_cset= field->charset();
THD *thd= field->table->in_use;
return should_do_narrowing(thd, field_cset, value_cset);
}
Utf8_narrow(Field *field_arg, bool is_applicable)
{
field= NULL;
if (is_applicable)
{
DTCollation mb3_from_mb4= utf8mb3_from_mb4.charset();
field= field_arg;
save_collation= field->dtcollation();
field->change_charset(mb3_from_mb4);
}
}
void stop()
{
if (field)
field->change_charset(save_collation);
#ifndef NDEBUG
field= NULL;
#endif
}
~Utf8_narrow()
{
DBUG_ASSERT(!field);
}
};
/*
@brief
Check if two fields can participate in a multiple equality using charset
narrowing.
@detail
Normally, check_simple_equality() checks this by calling:
left_field->eq_def(right_field)
This function does the same but takes into account we might use charset
narrowing:
- collations are not the same but rather an utf8mb{3,4}_general_ci pair
- for field lengths, should compare # characters, not #bytes.
*/
inline
bool fields_equal_using_narrowing(const THD *thd, const Field *left, const Field *right)
{
return
dynamic_cast<const Field_longstr*>(left) &&
dynamic_cast<const Field_longstr*>(right) &&
left->real_type() == right->real_type() &&
(Utf8_narrow::should_do_narrowing(left, right->charset()) ||
Utf8_narrow::should_do_narrowing(right, left->charset())) &&
left->char_length() == right->char_length();
};
#endif /* CSET_NARROWING_H_INCLUDED */

15
sql/field.cc
View file

@ -7508,7 +7508,8 @@ Field_longstr::cmp_to_string_with_stricter_collation(const Item_bool_func *cond,
return !cmp_is_done_using_type_handler_of_this(cond, item) ?
Data_type_compatibility::INCOMPATIBLE_DATA_TYPE :
(charset() != cond->compare_collation() &&
!(cond->compare_collation()->state & MY_CS_BINSORT)) ?
!(cond->compare_collation()->state & MY_CS_BINSORT) &&
!Utf8_narrow::should_do_narrowing(this, cond->compare_collation())) ?
Data_type_compatibility::INCOMPATIBLE_COLLATION :
Data_type_compatibility::OK;
}
@ -7519,6 +7520,18 @@ Field_longstr::can_optimize_keypart_ref(const Item_bool_func *cond,
const Item *item) const
{
DBUG_ASSERT(cmp_type() == STRING_RESULT);
/*
So, we have an equality: tbl.string_key = 'abc'
The comparison is the string comparison. Can we use index lookups to
find matching rows? We can do that when:
- The comparison uses the same collation as tbl.string_key
- the comparison uses binary collation, while tbl.string_key
uses some other collation.
In this case, we will find matches in some collation. For example, for
'abc' we may find 'abc', 'ABC', and 'äbc'.
But we're certain that will find the row with the identical binary, 'abc'.
*/
return cmp_to_string_with_stricter_collation(cond, item);
}

26
sql/item.cc
View file

@ -2522,7 +2522,8 @@ bool DTCollation::aggregate(const DTCollation &dt, uint flags)
/******************************/
static
void my_coll_agg_error(DTCollation &c1, DTCollation &c2, const char *fname)
void my_coll_agg_error(const DTCollation &c1, const DTCollation &c2,
const char *fname)
{
my_error(ER_CANT_AGGREGATE_2COLLATIONS,MYF(0),
c1.collation->coll_name.str, c1.derivation_name(),
@ -2605,10 +2606,17 @@ bool Type_std_attributes::agg_item_collations(DTCollation &c,
}
/*
@param single_err When nargs==1, use *single_err as the second aggregated
collation when producing error message.
*/
bool Type_std_attributes::agg_item_set_converter(const DTCollation &coll,
const LEX_CSTRING &fname,
Item **args, uint nargs,
uint flags, int item_sep)
uint flags, int item_sep,
const Single_coll_err
*single_err)
{
THD *thd= current_thd;
if (thd->lex->is_ps_or_view_context_analysis())
@ -2646,7 +2654,19 @@ bool Type_std_attributes::agg_item_set_converter(const DTCollation &coll,
args[0]= safe_args[0];
args[item_sep]= safe_args[1];
}
my_coll_agg_error(args, nargs, fname.str, item_sep);
if (nargs == 1 && single_err)
{
/*
Use *single_err to produce an error message mentioning two
collations.
*/
if (single_err->first)
my_coll_agg_error(args[0]->collation, single_err->coll, fname.str);
else
my_coll_agg_error(single_err->coll, args[0]->collation, fname.str);
}
else
my_coll_agg_error(args, nargs, fname.str, item_sep);
return TRUE;
}

41
sql/item.h
View file

@ -30,6 +30,8 @@
#include "sql_time.h"
#include "mem_root_array.h"
#include "cset_narrowing.h"
C_MODE_START
#include <ma_dyncol.h>
@ -5399,8 +5401,10 @@ protected:
public:
// This method is used by Arg_comparator
bool agg_arg_charsets_for_comparison(CHARSET_INFO **cs, Item **a, Item **b)
bool agg_arg_charsets_for_comparison(CHARSET_INFO **cs, Item **a, Item **b,
bool allow_narrowing)
{
THD *thd= current_thd;
DTCollation tmp;
if (tmp.set((*a)->collation, (*b)->collation, MY_COLL_CMP_CONV) ||
tmp.derivation == DERIVATION_NONE)
@ -5413,11 +5417,40 @@ public:
func_name());
return true;
}
if (allow_narrowing &&
(*a)->collation.derivation == (*b)->collation.derivation)
{
// allow_narrowing==true only for = and <=> comparisons.
if (Utf8_narrow::should_do_narrowing(thd, (*a)->collation.collation,
(*b)->collation.collation))
{
// a is a subset, b is a superset (e.g. utf8mb3 vs utf8mb4)
*cs= (*b)->collation.collation; // Compare using the wider cset
return false;
}
else
if (Utf8_narrow::should_do_narrowing(thd, (*b)->collation.collation,
(*a)->collation.collation))
{
// a is a superset, b is a subset (e.g. utf8mb4 vs utf8mb3)
*cs= (*a)->collation.collation; // Compare using the wider cset
return false;
}
}
/*
If necessary, convert both *a and *b to the collation in tmp:
*/
Single_coll_err error_for_a= {(*b)->collation, true};
Single_coll_err error_for_b= {(*a)->collation, false};
if (agg_item_set_converter(tmp, func_name_cstring(),
a, 1, MY_COLL_CMP_CONV, 1) ||
a, 1, MY_COLL_CMP_CONV, 1,
/*just for error message*/ &error_for_a) ||
agg_item_set_converter(tmp, func_name_cstring(),
b, 1, MY_COLL_CMP_CONV, 1))
return true;
b, 1, MY_COLL_CMP_CONV, 1,
/*just for error message*/ &error_for_b))
return true;
*cs= tmp.collation;
return false;
}

34
sql/item_cmpfunc.cc
View file

@ -463,10 +463,24 @@ bool Item_func::setup_args_and_comparator(THD *thd, Arg_comparator *cmp)
if (args[0]->cmp_type() == STRING_RESULT &&
args[1]->cmp_type() == STRING_RESULT)
{
DTCollation tmp;
if (agg_arg_charsets_for_comparison(tmp, args, 2))
CHARSET_INFO *tmp;
/*
Use charset narrowing only for equalities, as that would allow
to construct ref access.
Non-equality comparisons with constants work without charset narrowing,
the constant gets converted.
Non-equality comparisons with non-constants would need narrowing to
enable range optimizer to handle e.g.
t1.mb3key_col <= const_table.mb4_col
But this doesn't look important.
*/
bool allow_narrowing= MY_TEST(functype()==Item_func::EQ_FUNC ||
functype()==Item_func::EQUAL_FUNC);
if (agg_arg_charsets_for_comparison(&tmp, &args[0], &args[1],
allow_narrowing))
return true;
cmp->m_compare_collation= tmp.collation;
cmp->m_compare_collation= tmp;
}
// Convert constants when compared to int/year field
DBUG_ASSERT(functype() != LIKE_FUNC);
@ -589,9 +603,19 @@ bool Arg_comparator::set_cmp_func_string(THD *thd)
{
/*
We must set cmp_collation here as we may be called from for an automatic
generated item, like in natural join
generated item, like in natural join.
Allow reinterpted superset as subset.
*/
if (owner->agg_arg_charsets_for_comparison(&m_compare_collation, a, b))
bool allow_narrowing= false;
if (owner->type() == Item::FUNC_ITEM)
{
Item_func::Functype ftype= ((Item_func*)owner)->functype();
if (ftype == Item_func::EQUAL_FUNC || ftype==Item_func::EQ_FUNC)
allow_narrowing= true;
}
if (owner->agg_arg_charsets_for_comparison(&m_compare_collation, a, b,
allow_narrowing))
return true;
if ((*a)->type() == Item::FUNC_ITEM &&

19
sql/opt_range.cc
View file

@ -8998,11 +8998,28 @@ SEL_ARG *Field_str::get_mm_leaf(RANGE_OPT_PARAM *prm, KEY_PART *key_part,
const Item_bool_func *cond,
scalar_comparison_op op, Item *value)
{
int err;
DBUG_ENTER("Field_str::get_mm_leaf");
if (can_optimize_scalar_range(prm, key_part, cond, op, value) !=
Data_type_compatibility::OK)
DBUG_RETURN(0);
int err= value->save_in_field_no_warnings(this, 1);
{
/*
Do CharsetNarrowing if necessary
This means that we are temporary changing the character set of the
current key field to make key lookups possible.
This is needed when comparing an utf8mb3 key field with an utf8mb4 value.
See cset_narrowing.h for more details.
*/
bool do_narrowing=
Utf8_narrow::should_do_narrowing(this, value->collation.collation);
Utf8_narrow narrow(this, do_narrowing);
err= value->save_in_field_no_warnings(this, 1);
narrow.stop();
}
if ((op != SCALAR_CMP_EQUAL && is_real_null()) || err < 0)
DBUG_RETURN(&null_element);
if (err > 0)

1
sql/sql_priv.h
View file

@ -235,6 +235,7 @@
#define OPTIMIZER_SWITCH_COND_PUSHDOWN_FROM_HAVING (1ULL << 34)
#define OPTIMIZER_SWITCH_NOT_NULL_RANGE_SCAN (1ULL << 35)
#define OPTIMIZER_SWITCH_HASH_JOIN_CARDINALITY (1ULL << 36)
#define OPTIMIZER_SWITCH_CSET_NARROWING (1ULL << 37)
#define OPTIMIZER_SWITCH_DEFAULT (OPTIMIZER_SWITCH_INDEX_MERGE | \
OPTIMIZER_SWITCH_INDEX_MERGE_UNION | \

3
sql/sql_select.cc
View file

@ -15702,7 +15702,8 @@ bool check_simple_equality(THD *thd, const Item::Context &ctx,
Field *left_field= ((Item_field*) left_item)->field;
Field *right_field= ((Item_field*) right_item)->field;
if (!left_field->eq_def(right_field))
if (!left_field->eq_def(right_field) &&
!fields_equal_using_narrowing(thd, left_field, right_field))
return FALSE;
/* Search for multiple equalities containing field1 and/or field2 */

34
sql/sql_select.h
View file

@ -34,6 +34,8 @@
#include "opt_range.h" /* SQL_SELECT, QUICK_SELECT_I */
#include "filesort.h"
#include "cset_narrowing.h"
typedef struct st_join_table JOIN_TAB;
/* Values in optimize */
#define KEY_OPTIMIZE_EXISTS 1U
@ -1921,7 +1923,14 @@ public:
{
enum_check_fields org_count_cuted_fields= thd->count_cuted_fields;
Use_relaxed_field_copy urfc(to_field->table->in_use);
/* If needed, perform CharsetNarrowing for making ref access lookup keys. */
Utf8_narrow do_narrow(to_field, do_cset_narrowing);
store_key_result result= copy_inner();
do_narrow.stop();
thd->count_cuted_fields= org_count_cuted_fields;
return result;
}
@ -1931,6 +1940,12 @@ public:
uchar *null_ptr;
uchar err;
/*
This is set to true if we need to do Charset Narrowing when making a lookup
key.
*/
bool do_cset_narrowing= false;
virtual enum store_key_result copy_inner()=0;
};
@ -1950,6 +1965,7 @@ class store_key_field: public store_key
if (to_field)
{
copy_field.set(to_field,from_field,0);
setup_charset_narrowing();
}
}
@ -1960,6 +1976,15 @@ class store_key_field: public store_key
{
copy_field.set(to_field, fld_item->field, 0);
field_name= fld_item->full_name();
setup_charset_narrowing();
}
/* Setup CharsetNarrowing if necessary */
void setup_charset_narrowing()
{
do_cset_narrowing=
Utf8_narrow::should_do_narrowing(copy_field.to_field,
copy_field.from_field->charset());
}
protected:
@ -2000,7 +2025,12 @@ public:
:store_key(thd, to_field_arg, ptr,
null_ptr_arg ? null_ptr_arg : item_arg->maybe_null() ?
&err : (uchar*) 0, length), item(item_arg), use_value(val)
{}
{
/* Setup CharsetNarrowing to be done if necessary */
do_cset_narrowing=
Utf8_narrow::should_do_narrowing(to_field,
item->collation.collation);
}
store_key_item(store_key &arg, Item *new_item, bool val)
:store_key(arg), item(new_item), use_value(val)
{}
@ -2388,7 +2418,7 @@ Item_equal *find_item_equal(COND_EQUAL *cond_equal, Field *field,
extern bool test_if_ref(Item *,
Item_field *left_item,Item *right_item);
inline bool optimizer_flag(THD *thd, ulonglong flag)
inline bool optimizer_flag(const THD *thd, ulonglong flag)
{
return (thd->variables.optimizer_switch & flag);
}

8
sql/sql_type.h
View file

@ -3268,10 +3268,16 @@ public:
bool agg_item_collations(DTCollation &c, const LEX_CSTRING &name,
Item **items, uint nitems,
uint flags, int item_sep);
struct Single_coll_err
{
const DTCollation& coll;
bool first;
};
bool agg_item_set_converter(const DTCollation &coll,
const LEX_CSTRING &name,
Item **args, uint nargs,
uint flags, int item_sep);
uint flags, int item_sep,
const Single_coll_err *single_item_err= NULL);
/*
Collect arguments' character sets together.

1
sql/sys_vars.cc
View file

@ -2767,6 +2767,7 @@ export const char *optimizer_switch_names[]=
"condition_pushdown_from_having",
"not_null_range_scan",
"hash_join_cardinality",
"cset_narrowing",
"default",
NullS
};

12
strings/ctype-utf8.c
View file

@ -7973,4 +7973,16 @@ struct charset_info_st my_charset_utf8mb4_nopad_bin=
&my_collation_utf8mb4_nopad_bin_handler
};
/*
Take a my_wc_t character and convert it to utf8mb3 representation.
Characters that are not in Basic Multilingual Plane are replaced with
MY_CS_REPLACEMENT_CHARACTER.
*/
int my_wc_mb_utf8mb4_bmp_only(CHARSET_INFO *cs, my_wc_t wc, uchar *r, uchar *e)
{
if (wc > 0xFFFF)
wc= MY_CS_REPLACEMENT_CHARACTER;
return my_wc_mb_utf8mb4(cs, wc, r, e);
}
#endif /* HAVE_CHARSET_utf8mb4 */