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MDEV-6929: Port Facebook Prefix Index Queries Optimization

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Merge Facebook commit 154c579b828a60722a7d9477fc61868c07453d08
and e8f0052f9b112dc786bf9b957ed5b16a5749f7fd authored
by Steaphan Greene from https://github.com/facebook/mysql-5.6

Optimize prefix index queries to skip cluster index lookup when possible.

Currently InnoDB will always fetch the clustered index (primary key
index) for all prefix columns in an index, even when the value of a
particular record is smaller than the prefix length. This change
optimizes that case to use the record from the secondary index and avoid
the extra lookup.

Also adds two status vars that track how effective this is:

innodb_secondary_index_triggered_cluster_reads:
Times secondary index lookup triggered cluster lookup.

innodb_secondary_index_triggered_cluster_reads_avoided:
Times prefix optimization avoided triggering cluster lookup.
This commit is contained in:
Jan Lindström
2014-11-03 11:18:52 +02:00
parent 3c2c036248
commit cb37c55768
37 changed files with 870 additions and 51 deletions
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102
mysql-test/r/fast_prefix_index_fetch_innodb.result Normal file
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@@ -0,0 +1,102 @@
drop table if exists prefixinno;
set global innodb_prefix_index_cluster_optimization = ON;
show variables like 'innodb_prefix_index_cluster_optimization';
Variable_name Value
innodb_prefix_index_cluster_optimization ON
# Create a table with a large varchar field that we index the prefix
# of and ensure we only trigger cluster lookups when we expect it.
create table prefixinno (
id int not null,
fake_id int not null,
bigfield varchar(4096),
primary key(id),
index bigfield_idx (bigfield(32)),
index fake_id_bigfield_prefix (fake_id, bigfield(32))
) engine=innodb;
insert into prefixinno values (1, 1001, repeat('a', 1)),
(8, 1008, repeat('b', 8)),
(24, 1024, repeat('c', 24)),
(31, 1031, repeat('d', 31)),
(32, 1032, repeat('x', 32)),
(33, 1033, repeat('y', 33)),
(128, 1128, repeat('z', 128));
select * from prefixinno;
id fake_id bigfield
1 1001 a
8 1008 bbbbbbbb
24 1024 cccccccccccccccccccccccc
31 1031 ddddddddddddddddddddddddddddddd
32 1032 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
33 1033 yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
128 1128 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
# Baseline sanity check: 0, 0.
no-op query
no-op query
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Eligible for optimization.
id bigfield
31 ddddddddddddddddddddddddddddddd
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Eligible for optimization, access via fake_id only.
id bigfield
31 ddddddddddddddddddddddddddddddd
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Not eligible for optimization, access via fake_id of big row.
id bigfield
33 yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Not eligible for optimization.
id bigfield
32 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Not eligible for optimization.
id bigfield
33 yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Eligible, should not increment lookup counter.
id bigfield
8 bbbbbbbb
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Eligible, should not increment lookup counter.
id bigfield
24 cccccccccccccccccccccccc
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Should increment lookup counter.
id bigfield
128 zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# Disable optimization, confirm we still increment counter.
id bigfield
33 yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy
cluster_lookups_matched
1
cluster_lookups_avoided_matched
1
# make test suite happy by cleaning up our mess

2
mysql-test/suite/sys_vars/r/innodb_monitor_disable_basic.result
View File

@@ -40,6 +40,8 @@ buffer_pages_written disabled
buffer_index_pages_written disabled buffer_index_pages_written disabled
buffer_non_index_pages_written disabled buffer_non_index_pages_written disabled
buffer_pages_read disabled buffer_pages_read disabled
buffer_index_sec_rec_cluster_reads disabled
buffer_index_sec_rec_cluster_reads_avoided disabled
buffer_data_reads disabled buffer_data_reads disabled
buffer_data_written disabled buffer_data_written disabled
buffer_flush_batch_scanned disabled buffer_flush_batch_scanned disabled

2
mysql-test/suite/sys_vars/r/innodb_monitor_enable_basic.result
View File

@@ -40,6 +40,8 @@ buffer_pages_written disabled
buffer_index_pages_written disabled buffer_index_pages_written disabled
buffer_non_index_pages_written disabled buffer_non_index_pages_written disabled
buffer_pages_read disabled buffer_pages_read disabled
buffer_index_sec_rec_cluster_reads disabled
buffer_index_sec_rec_cluster_reads_avoided disabled
buffer_data_reads disabled buffer_data_reads disabled
buffer_data_written disabled buffer_data_written disabled
buffer_flush_batch_scanned disabled buffer_flush_batch_scanned disabled

2
mysql-test/suite/sys_vars/r/innodb_monitor_reset_all_basic.result
View File

@@ -40,6 +40,8 @@ buffer_pages_written disabled
buffer_index_pages_written disabled buffer_index_pages_written disabled
buffer_non_index_pages_written disabled buffer_non_index_pages_written disabled
buffer_pages_read disabled buffer_pages_read disabled
buffer_index_sec_rec_cluster_reads disabled
buffer_index_sec_rec_cluster_reads_avoided disabled
buffer_data_reads disabled buffer_data_reads disabled
buffer_data_written disabled buffer_data_written disabled
buffer_flush_batch_scanned disabled buffer_flush_batch_scanned disabled

2
mysql-test/suite/sys_vars/r/innodb_monitor_reset_basic.result
View File

@@ -40,6 +40,8 @@ buffer_pages_written disabled
buffer_index_pages_written disabled buffer_index_pages_written disabled
buffer_non_index_pages_written disabled buffer_non_index_pages_written disabled
buffer_pages_read disabled buffer_pages_read disabled
buffer_index_sec_rec_cluster_reads disabled
buffer_index_sec_rec_cluster_reads_avoided disabled
buffer_data_reads disabled buffer_data_reads disabled
buffer_data_written disabled buffer_data_written disabled
buffer_flush_batch_scanned disabled buffer_flush_batch_scanned disabled

122
mysql-test/suite/sys_vars/r/innodb_prefix_index_cluster_optimization_basic.result Normal file
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@@ -0,0 +1,122 @@
SET @start_global_value = @@global.innodb_prefix_index_cluster_optimization;
SELECT @start_global_value;
@start_global_value
0
#
# exists as global only
#
Valid values are 'ON' and 'OFF'
select @@global.innodb_prefix_index_cluster_optimization in (0, 1);
@@global.innodb_prefix_index_cluster_optimization in (0, 1)
1
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
0
select @@session.innodb_prefix_index_cluster_optimization;
ERROR HY000: Variable 'innodb_prefix_index_cluster_optimization' is a GLOBAL variable
show global variables like 'innodb_prefix_index_cluster_optimization';
Variable_name Value
innodb_prefix_index_cluster_optimization OFF
show session variables like 'innodb_prefix_index_cluster_optimization';
Variable_name Value
innodb_prefix_index_cluster_optimization OFF
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
#
# show that it's writable
#
set global innodb_prefix_index_cluster_optimization = 'OFF';
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
0
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
set @@global.innodb_prefix_index_cluster_optimization = 'ON';
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
1
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
set global innodb_prefix_index_cluster_optimization = 0;
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
0
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION OFF
set @@global.innodb_prefix_index_cluster_optimization = 1;
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
1
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
set session innodb_prefix_index_cluster_optimization = 'OFF';
ERROR HY000: Variable 'innodb_prefix_index_cluster_optimization' is a GLOBAL variable and should be set with SET GLOBAL
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
1
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
set @@session.innodb_prefix_index_cluster_optimization = 'ON';
ERROR HY000: Variable 'innodb_prefix_index_cluster_optimization' is a GLOBAL variable and should be set with SET GLOBAL
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
1
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
#
# incorrect types
#
set global innodb_prefix_index_cluster_optimization = 1.1;
ERROR 42000: Incorrect argument type to variable 'innodb_prefix_index_cluster_optimization'
set global innodb_prefix_index_cluster_optimization = 1e1;
ERROR 42000: Incorrect argument type to variable 'innodb_prefix_index_cluster_optimization'
set global innodb_prefix_index_cluster_optimization = 2;
ERROR 42000: Variable 'innodb_prefix_index_cluster_optimization' can't be set to the value of '2'
set global innodb_prefix_index_cluster_optimization = -3;
ERROR 42000: Variable 'innodb_prefix_index_cluster_optimization' can't be set to the value of '-3'
select @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
1
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
VARIABLE_NAME VARIABLE_VALUE
INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION ON
set global innodb_prefix_index_cluster_optimization = 'AUTO';
ERROR 42000: Variable 'innodb_prefix_index_cluster_optimization' can't be set to the value of 'AUTO'
#
# Cleanup
#
SET @@global.innodb_prefix_index_cluster_optimization = @start_global_value;
SELECT @@global.innodb_prefix_index_cluster_optimization;
@@global.innodb_prefix_index_cluster_optimization
0

14
mysql-test/suite/sys_vars/r/sysvars_innodb.result
View File

@@ -1461,6 +1461,20 @@ NUMERIC_BLOCK_SIZE 0
ENUM_VALUE_LIST NULL ENUM_VALUE_LIST NULL
READ_ONLY YES READ_ONLY YES
COMMAND_LINE_ARGUMENT OPTIONAL COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PREFIX_INDEX_CLUSTER_OPTIMIZATION
SESSION_VALUE NULL
GLOBAL_VALUE OFF
GLOBAL_VALUE_ORIGIN COMPILE-TIME
DEFAULT_VALUE OFF
VARIABLE_SCOPE GLOBAL
VARIABLE_TYPE BOOLEAN
VARIABLE_COMMENT Enable prefix optimization to sometimes avoid cluster index lookups.
NUMERIC_MIN_VALUE NULL
NUMERIC_MAX_VALUE NULL
NUMERIC_BLOCK_SIZE NULL
ENUM_VALUE_LIST NULL
READ_ONLY NO
COMMAND_LINE_ARGUMENT OPTIONAL
VARIABLE_NAME INNODB_PRINT_ALL_DEADLOCKS VARIABLE_NAME INNODB_PRINT_ALL_DEADLOCKS
SESSION_VALUE NULL SESSION_VALUE NULL
GLOBAL_VALUE OFF GLOBAL_VALUE OFF

76
mysql-test/suite/sys_vars/t/innodb_prefix_index_cluster_optimization_basic.test Normal file
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@@ -0,0 +1,76 @@
--source include/have_innodb.inc
SET @start_global_value = @@global.innodb_prefix_index_cluster_optimization;
SELECT @start_global_value;
--echo #
--echo # exists as global only
--echo #
--echo Valid values are 'ON' and 'OFF'
select @@global.innodb_prefix_index_cluster_optimization in (0, 1);
select @@global.innodb_prefix_index_cluster_optimization;
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
select @@session.innodb_prefix_index_cluster_optimization;
show global variables like 'innodb_prefix_index_cluster_optimization';
show session variables like 'innodb_prefix_index_cluster_optimization';
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
--echo #
--echo # show that it's writable
--echo #
set global innodb_prefix_index_cluster_optimization = 'OFF';
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
set @@global.innodb_prefix_index_cluster_optimization = 'ON';
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
set global innodb_prefix_index_cluster_optimization = 0;
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
set @@global.innodb_prefix_index_cluster_optimization = 1;
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
--error ER_GLOBAL_VARIABLE
set session innodb_prefix_index_cluster_optimization = 'OFF';
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
--error ER_GLOBAL_VARIABLE
set @@session.innodb_prefix_index_cluster_optimization = 'ON';
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
--echo #
--echo # incorrect types
--echo #
--error ER_WRONG_TYPE_FOR_VAR
set global innodb_prefix_index_cluster_optimization = 1.1;
--error ER_WRONG_TYPE_FOR_VAR
set global innodb_prefix_index_cluster_optimization = 1e1;
--error ER_WRONG_VALUE_FOR_VAR
set global innodb_prefix_index_cluster_optimization = 2;
--error ER_WRONG_VALUE_FOR_VAR
set global innodb_prefix_index_cluster_optimization = -3;
select @@global.innodb_prefix_index_cluster_optimization;
select * from information_schema.global_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
select * from information_schema.session_variables where variable_name = 'innodb_prefix_index_cluster_optimization';
--error ER_WRONG_VALUE_FOR_VAR
set global innodb_prefix_index_cluster_optimization = 'AUTO';
--echo #
--echo # Cleanup
--echo #
SET @@global.innodb_prefix_index_cluster_optimization = @start_global_value;
SELECT @@global.innodb_prefix_index_cluster_optimization;

150
mysql-test/t/fast_prefix_index_fetch_innodb.test Normal file
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@@ -0,0 +1,150 @@
-- source include/have_innodb.inc
--disable_warnings
drop table if exists prefixinno;
--enable_warnings
set global innodb_prefix_index_cluster_optimization = ON;
show variables like 'innodb_prefix_index_cluster_optimization';
--echo # Create a table with a large varchar field that we index the prefix
--echo # of and ensure we only trigger cluster lookups when we expect it.
create table prefixinno (
id int not null,
fake_id int not null,
bigfield varchar(4096),
primary key(id),
index bigfield_idx (bigfield(32)),
index fake_id_bigfield_prefix (fake_id, bigfield(32))
) engine=innodb;
insert into prefixinno values (1, 1001, repeat('a', 1)),
(8, 1008, repeat('b', 8)),
(24, 1024, repeat('c', 24)),
(31, 1031, repeat('d', 31)),
(32, 1032, repeat('x', 32)),
(33, 1033, repeat('y', 33)),
(128, 1128, repeat('z', 128));
select * from prefixinno;
let $show_count_statement = show status like 'innodb_secondary_index_triggered_cluster_reads';
let $show_opt_statement = show status like 'innodb_secondary_index_triggered_cluster_reads_avoided';
--disable_query_log
--echo # Baseline sanity check: 0, 0.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select "no-op query";
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # Eligible for optimization.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('d', 31);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_avoided_matched;
--echo # Eligible for optimization, access via fake_id only.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where fake_id = 1031;
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_avoided_matched;
--echo # Not eligible for optimization, access via fake_id of big row.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where fake_id = 1033;
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # Not eligible for optimization.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('x', 32);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # Not eligible for optimization.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('y', 33);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # Eligible, should not increment lookup counter.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('b', 8);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_avoided_matched;
--echo # Eligible, should not increment lookup counter.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('c', 24);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_avoided_matched;
--echo # Should increment lookup counter.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
select id, bigfield from prefixinno where bigfield = repeat('z', 128);
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # Disable optimization, confirm we still increment counter.
--let $base_count = query_get_value($show_count_statement, Value, 1)
--let $base_opt = query_get_value($show_opt_statement, Value, 1)
set global innodb_prefix_index_cluster_optimization = OFF;
select id, bigfield from prefixinno where fake_id = 1033;
--let $count = query_get_value($show_count_statement, Value, 1)
eval select $count - $base_count into @cluster_lookups;
select @cluster_lookups = 1 as cluster_lookups_matched;
--let $opt = query_get_value($show_opt_statement, Value, 1)
eval select $opt - $base_opt into @cluster_lookups;
select @cluster_lookups = 0 as cluster_lookups_avoided_matched;
--echo # make test suite happy by cleaning up our mess
drop table prefixinno;
set global innodb_prefix_index_cluster_optimization = OFF;

20
storage/innobase/dict/dict0dict.cc
View File

@@ -748,17 +748,24 @@ dict_index_get_nth_col_or_prefix_pos(
/*=================================*/ /*=================================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n, /*!< in: column number */ ulint n, /*!< in: column number */
ibool inc_prefix) /*!< in: TRUE=consider ibool inc_prefix, /*!< in: TRUE=consider
column prefixes too */ column prefixes too */
ulint* prefix_col_pos) /*!< out: col num if prefix */
{ {
const dict_field_t* field; const dict_field_t* field;
const dict_col_t* col; const dict_col_t* col;
ulint pos; ulint pos;
ulint n_fields; ulint n_fields;
ulint prefixed_pos_dummy;
ut_ad(index); ut_ad(index);
ut_ad(index->magic_n == DICT_INDEX_MAGIC_N); ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
if (!prefix_col_pos) {
prefix_col_pos = &prefixed_pos_dummy;
}
*prefix_col_pos = ULINT_UNDEFINED;
col = dict_table_get_nth_col(index->table, n); col = dict_table_get_nth_col(index->table, n);
if (dict_index_is_clust(index)) { if (dict_index_is_clust(index)) {
@@ -771,10 +778,11 @@ dict_index_get_nth_col_or_prefix_pos(
for (pos = 0; pos < n_fields; pos++) { for (pos = 0; pos < n_fields; pos++) {
field = dict_index_get_nth_field(index, pos); field = dict_index_get_nth_field(index, pos);
if (col == field->col if (col == field->col) {
&& (inc_prefix || field->prefix_len == 0)) { *prefix_col_pos = pos;
if (inc_prefix || field->prefix_len == 0) {
return(pos); return(pos);
}
} }
} }
@@ -919,7 +927,7 @@ dict_table_get_nth_col_pos(
ulint n) /*!< in: column number */ ulint n) /*!< in: column number */
{ {
return(dict_index_get_nth_col_pos(dict_table_get_first_index(table), return(dict_index_get_nth_col_pos(dict_table_get_first_index(table),
n)); n, NULL));
} }
/********************************************************************//** /********************************************************************//**

38
storage/innobase/handler/ha_innodb.cc
View File

@@ -799,6 +799,14 @@ static SHOW_VAR innodb_status_variables[]= {
{"onlineddl_pct_progress", {"onlineddl_pct_progress",
(char*) &export_vars.innodb_onlineddl_pct_progress, SHOW_LONG}, (char*) &export_vars.innodb_onlineddl_pct_progress, SHOW_LONG},
/* Times secondary index lookup triggered cluster lookup and
times prefix optimization avoided triggering cluster lookup */
{"secondary_index_triggered_cluster_reads",
(char*) &export_vars.innodb_sec_rec_cluster_reads, SHOW_LONG},
{"secondary_index_triggered_cluster_reads_avoided",
(char*) &export_vars.innodb_sec_rec_cluster_reads_avoided, SHOW_LONG},
{NullS, NullS, SHOW_LONG} {NullS, NullS, SHOW_LONG}
}; };
@@ -7044,11 +7052,20 @@ build_template_field(
templ->col_no = i; templ->col_no = i;
templ->clust_rec_field_no = dict_col_get_clust_pos(col, clust_index); templ->clust_rec_field_no = dict_col_get_clust_pos(col, clust_index);
ut_a(templ->clust_rec_field_no != ULINT_UNDEFINED); ut_a(templ->clust_rec_field_no != ULINT_UNDEFINED);
templ->rec_field_is_prefix = FALSE;
if (dict_index_is_clust(index)) { if (dict_index_is_clust(index)) {
templ->rec_field_no = templ->clust_rec_field_no; templ->rec_field_no = templ->clust_rec_field_no;
templ->rec_prefix_field_no = ULINT_UNDEFINED;
} else { } else {
templ->rec_field_no = dict_index_get_nth_col_pos(index, i); /* If we're in a secondary index, keep track
* of the original index position even if this
* is just a prefix index; we will use this
* later to avoid a cluster index lookup in
* some cases.*/
templ->rec_field_no = dict_index_get_nth_col_pos(index, i,
&templ->rec_prefix_field_no);
} }
if (field->real_maybe_null()) { if (field->real_maybe_null()) {
@@ -7079,6 +7096,13 @@ build_template_field(
if (!dict_index_is_clust(index) if (!dict_index_is_clust(index)
&& templ->rec_field_no == ULINT_UNDEFINED) { && templ->rec_field_no == ULINT_UNDEFINED) {
prebuilt->need_to_access_clustered = TRUE; prebuilt->need_to_access_clustered = TRUE;
if (templ->rec_prefix_field_no != ULINT_UNDEFINED) {
dict_field_t* field = dict_index_get_nth_field(
index,
templ->rec_prefix_field_no);
templ->rec_field_is_prefix = (field->prefix_len != 0);
}
} }
if (prebuilt->mysql_prefix_len < templ->mysql_col_offset if (prebuilt->mysql_prefix_len < templ->mysql_col_offset
@@ -7240,7 +7264,8 @@ ha_innobase::build_template(
} else { } else {
templ->icp_rec_field_no templ->icp_rec_field_no
= dict_index_get_nth_col_pos( = dict_index_get_nth_col_pos(
prebuilt->index, i); prebuilt->index, i,
NULL);
} }
if (dict_index_is_clust(prebuilt->index)) { if (dict_index_is_clust(prebuilt->index)) {
@@ -7270,7 +7295,7 @@ ha_innobase::build_template(
templ->icp_rec_field_no templ->icp_rec_field_no
= dict_index_get_nth_col_or_prefix_pos( = dict_index_get_nth_col_or_prefix_pos(
prebuilt->index, i, TRUE); prebuilt->index, i, TRUE, NULL);
ut_ad(templ->icp_rec_field_no ut_ad(templ->icp_rec_field_no
!= ULINT_UNDEFINED); != ULINT_UNDEFINED);
@@ -18475,6 +18500,12 @@ static MYSQL_SYSVAR_ULONG(
1000000, 0); /* Maximum value */ 1000000, 0); /* Maximum value */
#endif /* HAVE_ATOMIC_BUILTINS */ #endif /* HAVE_ATOMIC_BUILTINS */
static MYSQL_SYSVAR_BOOL(prefix_index_cluster_optimization,
srv_prefix_index_cluster_optimization,
PLUGIN_VAR_OPCMDARG,
"Enable prefix optimization to sometimes avoid cluster index lookups.",
NULL, NULL, FALSE);
static MYSQL_SYSVAR_ULONG(thread_sleep_delay, srv_thread_sleep_delay, static MYSQL_SYSVAR_ULONG(thread_sleep_delay, srv_thread_sleep_delay,
PLUGIN_VAR_RQCMDARG, PLUGIN_VAR_RQCMDARG,
"Time of innodb thread sleeping before joining InnoDB queue (usec). " "Time of innodb thread sleeping before joining InnoDB queue (usec). "
@@ -18908,6 +18939,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
#ifdef HAVE_ATOMIC_BUILTINS #ifdef HAVE_ATOMIC_BUILTINS
MYSQL_SYSVAR(adaptive_max_sleep_delay), MYSQL_SYSVAR(adaptive_max_sleep_delay),
#endif /* HAVE_ATOMIC_BUILTINS */ #endif /* HAVE_ATOMIC_BUILTINS */
MYSQL_SYSVAR(prefix_index_cluster_optimization),
MYSQL_SYSVAR(thread_sleep_delay), MYSQL_SYSVAR(thread_sleep_delay),
MYSQL_SYSVAR(autoinc_lock_mode), MYSQL_SYSVAR(autoinc_lock_mode),
MYSQL_SYSVAR(version), MYSQL_SYSVAR(version),

6
storage/innobase/handler/handler0alter.cc
View File

@@ -1194,7 +1194,8 @@ innobase_rec_to_mysql(
field->reset(); field->reset();
ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE); ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE,
NULL);
if (ipos == ULINT_UNDEFINED if (ipos == ULINT_UNDEFINED
|| rec_offs_nth_extern(offsets, ipos)) { || rec_offs_nth_extern(offsets, ipos)) {
@@ -1246,7 +1247,8 @@ innobase_fields_to_mysql(
field->reset(); field->reset();
ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE); ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE,
NULL);
if (ipos == ULINT_UNDEFINED if (ipos == ULINT_UNDEFINED
|| dfield_is_ext(&fields[ipos]) || dfield_is_ext(&fields[ipos])

11
storage/innobase/include/dict0dict.h
View File

@@ -1159,8 +1159,9 @@ ulint
dict_index_get_nth_col_pos( dict_index_get_nth_col_pos(
/*=======================*/ /*=======================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n) /*!< in: column number */ ulint n, /*!< in: column number */
__attribute__((nonnull, warn_unused_result)); ulint* prefix_col_pos) /*!< out: col num if prefix */
__attribute__((nonnull(1), warn_unused_result));
/********************************************************************//** /********************************************************************//**
Looks for column n in an index. Looks for column n in an index.
@return position in internal representation of the index; @return position in internal representation of the index;
@@ -1171,9 +1172,11 @@ dict_index_get_nth_col_or_prefix_pos(
/*=================================*/ /*=================================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n, /*!< in: column number */ ulint n, /*!< in: column number */
ibool inc_prefix) /*!< in: TRUE=consider ibool inc_prefix, /*!< in: TRUE=consider
column prefixes too */ column prefixes too */
__attribute__((nonnull, warn_unused_result)); ulint* prefix_col_pos) /*!< out: col num if prefix */
__attribute__((nonnull(1), warn_unused_result));
/********************************************************************//** /********************************************************************//**
Returns TRUE if the index contains a column or a prefix of that column. Returns TRUE if the index contains a column or a prefix of that column.
@return TRUE if contains the column or its prefix */ @return TRUE if contains the column or its prefix */

9
storage/innobase/include/dict0dict.ic
View File

@@ -1221,7 +1221,8 @@ dict_index_get_sys_col_pos(
} }
return(dict_index_get_nth_col_pos( return(dict_index_get_nth_col_pos(
index, dict_table_get_sys_col_no(index->table, type))); index, dict_table_get_sys_col_no(index->table, type),
NULL));
} }
/*********************************************************************//** /*********************************************************************//**
@@ -1273,9 +1274,11 @@ ulint
dict_index_get_nth_col_pos( dict_index_get_nth_col_pos(
/*=======================*/ /*=======================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n) /*!< in: column number */ ulint n, /*!< in: column number */
ulint* prefix_col_pos) /*!< out: col num if prefix */
{ {
return(dict_index_get_nth_col_or_prefix_pos(index, n, FALSE)); return(dict_index_get_nth_col_or_prefix_pos(index, n, FALSE,
prefix_col_pos));
} }
#ifndef UNIV_HOTBACKUP #ifndef UNIV_HOTBACKUP

10
storage/innobase/include/row0mysql.h
View File

@@ -606,6 +606,12 @@ struct mysql_row_templ_t {
Innobase record in the current index; Innobase record in the current index;
not defined if template_type is not defined if template_type is
ROW_MYSQL_WHOLE_ROW */ ROW_MYSQL_WHOLE_ROW */
ibool rec_field_is_prefix; /* is this field in a prefix index? */
ulint rec_prefix_field_no; /* record field, even if just a
prefix; same as rec_field_no when not a
prefix, otherwise rec_field_no is
ULINT_UNDEFINED but this is the true
field number*/
ulint clust_rec_field_no; /*!< field number of the column in an ulint clust_rec_field_no; /*!< field number of the column in an
Innobase record in the clustered index; Innobase record in the clustered index;
not defined if template_type is not defined if template_type is
@@ -707,7 +713,9 @@ struct row_prebuilt_t {
columns through a secondary index columns through a secondary index
and at least one column is not in and at least one column is not in
the secondary index, then this is the secondary index, then this is
set to TRUE */ set to TRUE; note that sometimes this
is set but we later optimize out the
clustered index lookup */
unsigned templ_contains_blob:1;/*!< TRUE if the template contains unsigned templ_contains_blob:1;/*!< TRUE if the template contains
a column with DATA_BLOB == a column with DATA_BLOB ==
get_innobase_type_from_mysql_type(); get_innobase_type_from_mysql_type();

2
storage/innobase/include/srv0mon.h
View File

@@ -167,6 +167,8 @@ enum monitor_id_t {
MONITOR_OVLD_INDEX_PAGES_WRITTEN, MONITOR_OVLD_INDEX_PAGES_WRITTEN,
MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN, MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN,
MONITOR_OVLD_PAGES_READ, MONITOR_OVLD_PAGES_READ,
MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS,
MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED,
MONITOR_OVLD_BYTE_READ, MONITOR_OVLD_BYTE_READ,
MONITOR_OVLD_BYTE_WRITTEN, MONITOR_OVLD_BYTE_WRITTEN,
MONITOR_FLUSH_BATCH_SCANNED, MONITOR_FLUSH_BATCH_SCANNED,

13
storage/innobase/include/srv0srv.h
View File

@@ -157,6 +157,12 @@ struct srv_stats_t {
/** Number of rows inserted */ /** Number of rows inserted */
ulint_ctr_64_t n_rows_inserted; ulint_ctr_64_t n_rows_inserted;
/** Number of times secondary index lookup triggered cluster lookup */
ulint_ctr_64_t n_sec_rec_cluster_reads;
/** Number of times prefix optimization avoided triggering cluster lookup */
ulint_ctr_64_t n_sec_rec_cluster_reads_avoided;
}; };
extern const char* srv_main_thread_op_info; extern const char* srv_main_thread_op_info;
@@ -304,6 +310,10 @@ extern ulong srv_auto_extend_increment;
extern ibool srv_created_new_raw; extern ibool srv_created_new_raw;
/* Optimize prefix index queries to skip cluster index lookup when possible */
/* Enables or disables this prefix optimization. Disabled by default. */
extern my_bool srv_prefix_index_cluster_optimization;
/** Maximum number of srv_n_log_files, or innodb_log_files_in_group */ /** Maximum number of srv_n_log_files, or innodb_log_files_in_group */
#define SRV_N_LOG_FILES_MAX 100 #define SRV_N_LOG_FILES_MAX 100
extern ulong srv_n_log_files; extern ulong srv_n_log_files;
@@ -969,6 +979,9 @@ struct export_var_t{
compression */ compression */
ib_int64_t innodb_pages_page_compression_error;/*!< Number of page ib_int64_t innodb_pages_page_compression_error;/*!< Number of page
compression errors */ compression errors */
ulint innodb_sec_rec_cluster_reads; /*!< srv_sec_rec_cluster_reads */
ulint innodb_sec_rec_cluster_reads_avoided; /*!< srv_sec_rec_cluster_reads_avoided */
}; };
/** Thread slot in the thread table. */ /** Thread slot in the thread table. */

6
storage/innobase/pars/pars0opt.cc
View File

@@ -948,12 +948,14 @@ opt_find_all_cols(
/* Fill in the field_no fields in sym_node */ /* Fill in the field_no fields in sym_node */
sym_node->field_nos[SYM_CLUST_FIELD_NO] = dict_index_get_nth_col_pos( sym_node->field_nos[SYM_CLUST_FIELD_NO] = dict_index_get_nth_col_pos(
dict_table_get_first_index(index->table), sym_node->col_no); dict_table_get_first_index(index->table), sym_node->col_no,
NULL);
if (!dict_index_is_clust(index)) { if (!dict_index_is_clust(index)) {
ut_a(plan); ut_a(plan);
col_pos = dict_index_get_nth_col_pos(index, sym_node->col_no); col_pos = dict_index_get_nth_col_pos(index, sym_node->col_no,
NULL);
if (col_pos == ULINT_UNDEFINED) { if (col_pos == ULINT_UNDEFINED) {

3
storage/innobase/pars/pars0pars.cc
View File

@@ -1232,7 +1232,8 @@ pars_process_assign_list(
col_sym = assign_node->col; col_sym = assign_node->col;
upd_field_set_field_no(upd_field, dict_index_get_nth_col_pos( upd_field_set_field_no(upd_field, dict_index_get_nth_col_pos(
clust_index, col_sym->col_no), clust_index, col_sym->col_no,
NULL),
clust_index, NULL); clust_index, NULL);
upd_field->exp = assign_node->val; upd_field->exp = assign_node->val;

71
storage/innobase/row/row0sel.cc
View File

@@ -56,6 +56,7 @@ Created 12/19/1997 Heikki Tuuri
#include "row0mysql.h" #include "row0mysql.h"
#include "read0read.h" #include "read0read.h"
#include "buf0lru.h" #include "buf0lru.h"
#include "srv0srv.h"
#include "ha_prototypes.h" #include "ha_prototypes.h"
#include "m_string.h" /* for my_sys.h */ #include "m_string.h" /* for my_sys.h */
#include "my_sys.h" /* DEBUG_SYNC_C */ #include "my_sys.h" /* DEBUG_SYNC_C */
@@ -2936,9 +2937,14 @@ row_sel_store_mysql_rec(
: templ->rec_field_no; : templ->rec_field_no;
/* We should never deliver column prefixes to MySQL, /* We should never deliver column prefixes to MySQL,
except for evaluating innobase_index_cond(). */ except for evaluating innobase_index_cond(). */
/* ...actually, we do want to do this in order to
support the prefix query optimization.
ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len
== 0); == 0);
...so we disable this assert. */
if (!row_sel_store_mysql_field(mysql_rec, prebuilt, if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
rec, index, offsets, rec, index, offsets,
field_no, templ)) { field_no, templ)) {
@@ -3031,6 +3037,8 @@ row_sel_get_clust_rec_for_mysql(
dberr_t err; dberr_t err;
trx_t* trx; trx_t* trx;
srv_stats.n_sec_rec_cluster_reads.inc();
*out_rec = NULL; *out_rec = NULL;
trx = thr_get_trx(thr); trx = thr_get_trx(thr);
@@ -3686,6 +3694,7 @@ row_search_for_mysql(
ulint* offsets = offsets_; ulint* offsets = offsets_;
ibool table_lock_waited = FALSE; ibool table_lock_waited = FALSE;
byte* next_buf = 0; byte* next_buf = 0;
ibool use_clustered_index = FALSE;
rec_offs_init(offsets_); rec_offs_init(offsets_);
@@ -4709,10 +4718,68 @@ locks_ok:
} }
/* Get the clustered index record if needed, if we did not do the /* Get the clustered index record if needed, if we did not do the
search using the clustered index. */ search using the clustered index... */
if (index != clust_index && prebuilt->need_to_access_clustered) { use_clustered_index =
(index != clust_index && prebuilt->need_to_access_clustered);
if (use_clustered_index && srv_prefix_index_cluster_optimization
&& prebuilt->n_template <= index->n_fields) {
/* ...but, perhaps avoid the clustered index lookup if
all of the following are true:
1) all columns are in the secondary index
2) all values for columns that are prefix-only
indexes are shorter than the prefix size
This optimization can avoid many IOs for certain schemas.
*/
ibool row_contains_all_values = TRUE;
int i;
for (i = 0; i < prebuilt->n_template; i++) {
/* Condition (1) from above: is the field in the
index (prefix or not)? */
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
ulint secondary_index_field_no =
templ->rec_prefix_field_no;
if (secondary_index_field_no == ULINT_UNDEFINED) {
row_contains_all_values = FALSE;
break;
}
/* Condition (2) from above: if this is a
prefix, is this row's value size shorter
than the prefix? */
if (templ->rec_field_is_prefix) {
ulint record_size = rec_offs_nth_size(
offsets,
secondary_index_field_no);
const dict_field_t *field =
dict_index_get_nth_field(
index,
secondary_index_field_no);
ut_a(field->prefix_len > 0);
if (record_size >= field->prefix_len) {
row_contains_all_values = FALSE;
break;
}
}
}
/* If (1) and (2) were true for all columns above, use
rec_prefix_field_no instead of rec_field_no, and skip
the clustered lookup below. */
if (row_contains_all_values) {
for (i = 0; i < prebuilt->n_template; i++) {
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
templ->rec_field_no =
templ->rec_prefix_field_no;
ut_a(templ->rec_field_no != ULINT_UNDEFINED);
}
use_clustered_index = FALSE;
srv_stats.n_sec_rec_cluster_reads_avoided.inc();
}
}
if (use_clustered_index) {
requires_clust_rec: requires_clust_rec:
ut_ad(index != clust_index); ut_ad(index != clust_index);
/* We use a 'goto' to the preceding label if a consistent /* We use a 'goto' to the preceding label if a consistent

22
storage/innobase/srv/srv0mon.cc
View File

@@ -309,6 +309,18 @@ static monitor_info_t innodb_counter_info[] =
MONITOR_EXISTING | MONITOR_DEFAULT_ON), MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_PAGES_READ}, MONITOR_DEFAULT_START, MONITOR_OVLD_PAGES_READ},
{"buffer_index_sec_rec_cluster_reads", "buffer",
"Number of secondary record reads triggered cluster read",
static_cast<monitor_type_t>(
MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS},
{"buffer_index_sec_rec_cluster_reads_avoided", "buffer",
"Number of secondary record reads avoided triggering cluster read",
static_cast<monitor_type_t>(
MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED},
{"buffer_data_reads", "buffer", {"buffer_data_reads", "buffer",
"Amount of data read in bytes (innodb_data_reads)", "Amount of data read in bytes (innodb_data_reads)",
static_cast<monitor_type_t>( static_cast<monitor_type_t>(
@@ -1646,6 +1658,16 @@ srv_mon_process_existing_counter(
value = stat.n_pages_read; value = stat.n_pages_read;
break; break;
/* Number of times secondary index lookup triggered cluster lookup */
case MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS:
value = srv_stats.n_sec_rec_cluster_reads;
break;
/* Number of times prefix optimization avoided triggering cluster
lookup */
case MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED:
value = srv_stats.n_sec_rec_cluster_reads_avoided;
break;
/* innodb_data_reads, the total number of data reads */ /* innodb_data_reads, the total number of data reads */
case MONITOR_OVLD_BYTE_READ: case MONITOR_OVLD_BYTE_READ:
value = srv_stats.data_read; value = srv_stats.data_read;

9
storage/innobase/srv/srv0srv.cc
View File

@@ -356,6 +356,10 @@ UNIV_INTERN ulint srv_fast_shutdown = 0;
/* Generate a innodb_status.<pid> file */ /* Generate a innodb_status.<pid> file */
UNIV_INTERN ibool srv_innodb_status = FALSE; UNIV_INTERN ibool srv_innodb_status = FALSE;
/* Optimize prefix index queries to skip cluster index lookup when possible */
/* Enables or disables this prefix optimization. Disabled by default. */
UNIV_INTERN my_bool srv_prefix_index_cluster_optimization = 0;
/* When estimating number of different key values in an index, sample /* When estimating number of different key values in an index, sample
this many index pages, there are 2 ways to calculate statistics: this many index pages, there are 2 ways to calculate statistics:
* persistent stats that are calculated by ANALYZE TABLE and saved * persistent stats that are calculated by ANALYZE TABLE and saved
@@ -1566,6 +1570,11 @@ srv_export_innodb_status(void)
} }
#endif /* UNIV_DEBUG */ #endif /* UNIV_DEBUG */
export_vars.innodb_sec_rec_cluster_reads =
srv_stats.n_sec_rec_cluster_reads;
export_vars.innodb_sec_rec_cluster_reads_avoided =
srv_stats.n_sec_rec_cluster_reads_avoided;
mutex_exit(&srv_innodb_monitor_mutex); mutex_exit(&srv_innodb_monitor_mutex);
} }

3
storage/innobase/trx/trx0rec.cc
View File

@@ -781,7 +781,8 @@ trx_undo_page_report_modify(
} }
pos = dict_index_get_nth_col_pos(index, pos = dict_index_get_nth_col_pos(index,
col_no); col_no,
NULL);
ptr += mach_write_compressed(ptr, pos); ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */ /* Save the old value of field */

20
storage/xtradb/dict/dict0dict.cc
View File

@@ -748,17 +748,24 @@ dict_index_get_nth_col_or_prefix_pos(
/*=================================*/ /*=================================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n, /*!< in: column number */ ulint n, /*!< in: column number */
ibool inc_prefix) /*!< in: TRUE=consider ibool inc_prefix, /*!< in: TRUE=consider
column prefixes too */ column prefixes too */
ulint* prefix_col_pos) /*!< out: col num if prefix */
{ {
const dict_field_t* field; const dict_field_t* field;
const dict_col_t* col; const dict_col_t* col;
ulint pos; ulint pos;
ulint n_fields; ulint n_fields;
ulint prefixed_pos_dummy;
ut_ad(index); ut_ad(index);
ut_ad(index->magic_n == DICT_INDEX_MAGIC_N); ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);
if (!prefix_col_pos) {
prefix_col_pos = &prefixed_pos_dummy;
}
*prefix_col_pos = ULINT_UNDEFINED;
col = dict_table_get_nth_col(index->table, n); col = dict_table_get_nth_col(index->table, n);
if (dict_index_is_clust(index)) { if (dict_index_is_clust(index)) {
@@ -771,10 +778,11 @@ dict_index_get_nth_col_or_prefix_pos(
for (pos = 0; pos < n_fields; pos++) { for (pos = 0; pos < n_fields; pos++) {
field = dict_index_get_nth_field(index, pos); field = dict_index_get_nth_field(index, pos);
if (col == field->col if (col == field->col) {
&& (inc_prefix || field->prefix_len == 0)) { *prefix_col_pos = pos;
if (inc_prefix || field->prefix_len == 0) {
return(pos); return(pos);
}
} }
} }
@@ -919,7 +927,7 @@ dict_table_get_nth_col_pos(
ulint n) /*!< in: column number */ ulint n) /*!< in: column number */
{ {
return(dict_index_get_nth_col_pos(dict_table_get_first_index(table), return(dict_index_get_nth_col_pos(dict_table_get_first_index(table),
n)); n, NULL));
} }
/********************************************************************//** /********************************************************************//**

38
storage/xtradb/handler/ha_innodb.cc
View File

@@ -998,6 +998,14 @@ static SHOW_VAR innodb_status_variables[]= {
{"onlineddl_pct_progress", {"onlineddl_pct_progress",
(char*) &export_vars.innodb_onlineddl_pct_progress, SHOW_LONG}, (char*) &export_vars.innodb_onlineddl_pct_progress, SHOW_LONG},
/* Times secondary index lookup triggered cluster lookup and
times prefix optimization avoided triggering cluster lookup */
{"secondary_index_triggered_cluster_reads",
(char*) &export_vars.innodb_sec_rec_cluster_reads, SHOW_LONG},
{"secondary_index_triggered_cluster_reads_avoided",
(char*) &export_vars.innodb_sec_rec_cluster_reads_avoided, SHOW_LONG},
{NullS, NullS, SHOW_LONG} {NullS, NullS, SHOW_LONG}
}; };
@@ -7615,11 +7623,20 @@ build_template_field(
templ->col_no = i; templ->col_no = i;
templ->clust_rec_field_no = dict_col_get_clust_pos(col, clust_index); templ->clust_rec_field_no = dict_col_get_clust_pos(col, clust_index);
ut_a(templ->clust_rec_field_no != ULINT_UNDEFINED); ut_a(templ->clust_rec_field_no != ULINT_UNDEFINED);
templ->rec_field_is_prefix = FALSE;
if (dict_index_is_clust(index)) { if (dict_index_is_clust(index)) {
templ->rec_field_no = templ->clust_rec_field_no; templ->rec_field_no = templ->clust_rec_field_no;
templ->rec_prefix_field_no = ULINT_UNDEFINED;
} else { } else {
templ->rec_field_no = dict_index_get_nth_col_pos(index, i); /* If we're in a secondary index, keep track
* of the original index position even if this
* is just a prefix index; we will use this
* later to avoid a cluster index lookup in
* some cases.*/
templ->rec_field_no = dict_index_get_nth_col_pos(index, i,
&templ->rec_prefix_field_no);
} }
if (field->real_maybe_null()) { if (field->real_maybe_null()) {
@@ -7650,6 +7667,13 @@ build_template_field(
if (!dict_index_is_clust(index) if (!dict_index_is_clust(index)
&& templ->rec_field_no == ULINT_UNDEFINED) { && templ->rec_field_no == ULINT_UNDEFINED) {
prebuilt->need_to_access_clustered = TRUE; prebuilt->need_to_access_clustered = TRUE;
if (templ->rec_prefix_field_no != ULINT_UNDEFINED) {
dict_field_t* field = dict_index_get_nth_field(
index,
templ->rec_prefix_field_no);
templ->rec_field_is_prefix = (field->prefix_len != 0);
}
} }
if (prebuilt->mysql_prefix_len < templ->mysql_col_offset if (prebuilt->mysql_prefix_len < templ->mysql_col_offset
@@ -7811,7 +7835,8 @@ ha_innobase::build_template(
} else { } else {
templ->icp_rec_field_no templ->icp_rec_field_no
= dict_index_get_nth_col_pos( = dict_index_get_nth_col_pos(
prebuilt->index, i); prebuilt->index, i,
NULL);
} }
if (dict_index_is_clust(prebuilt->index)) { if (dict_index_is_clust(prebuilt->index)) {
@@ -7841,7 +7866,7 @@ ha_innobase::build_template(
templ->icp_rec_field_no templ->icp_rec_field_no
= dict_index_get_nth_col_or_prefix_pos( = dict_index_get_nth_col_or_prefix_pos(
prebuilt->index, i, TRUE); prebuilt->index, i, TRUE, NULL);
ut_ad(templ->icp_rec_field_no ut_ad(templ->icp_rec_field_no
!= ULINT_UNDEFINED); != ULINT_UNDEFINED);
@@ -19705,6 +19730,12 @@ static MYSQL_SYSVAR_ULONG(
1000000, 0); /* Maximum value */ 1000000, 0); /* Maximum value */
#endif /* HAVE_ATOMIC_BUILTINS */ #endif /* HAVE_ATOMIC_BUILTINS */
static MYSQL_SYSVAR_BOOL(prefix_index_cluster_optimization,
srv_prefix_index_cluster_optimization,
PLUGIN_VAR_OPCMDARG,
"Enable prefix optimization to sometimes avoid cluster index lookups.",
NULL, NULL, FALSE);
static MYSQL_SYSVAR_ULONG(thread_sleep_delay, srv_thread_sleep_delay, static MYSQL_SYSVAR_ULONG(thread_sleep_delay, srv_thread_sleep_delay,
PLUGIN_VAR_RQCMDARG, PLUGIN_VAR_RQCMDARG,
"Time of innodb thread sleeping before joining InnoDB queue (usec). " "Time of innodb thread sleeping before joining InnoDB queue (usec). "
@@ -20207,6 +20238,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
#ifdef HAVE_ATOMIC_BUILTINS #ifdef HAVE_ATOMIC_BUILTINS
MYSQL_SYSVAR(adaptive_max_sleep_delay), MYSQL_SYSVAR(adaptive_max_sleep_delay),
#endif /* HAVE_ATOMIC_BUILTINS */ #endif /* HAVE_ATOMIC_BUILTINS */
MYSQL_SYSVAR(prefix_index_cluster_optimization),
MYSQL_SYSVAR(thread_sleep_delay), MYSQL_SYSVAR(thread_sleep_delay),
MYSQL_SYSVAR(autoinc_lock_mode), MYSQL_SYSVAR(autoinc_lock_mode),
MYSQL_SYSVAR(show_verbose_locks), MYSQL_SYSVAR(show_verbose_locks),

6
storage/xtradb/handler/handler0alter.cc
View File

@@ -1199,7 +1199,8 @@ innobase_rec_to_mysql(
field->reset(); field->reset();
ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE); ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE,
NULL);
if (ipos == ULINT_UNDEFINED if (ipos == ULINT_UNDEFINED
|| rec_offs_nth_extern(offsets, ipos)) { || rec_offs_nth_extern(offsets, ipos)) {
@@ -1251,7 +1252,8 @@ innobase_fields_to_mysql(
field->reset(); field->reset();
ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE); ipos = dict_index_get_nth_col_or_prefix_pos(index, i, TRUE,
NULL);
if (ipos == ULINT_UNDEFINED if (ipos == ULINT_UNDEFINED
|| dfield_is_ext(&fields[ipos]) || dfield_is_ext(&fields[ipos])

11
storage/xtradb/include/dict0dict.h
View File

@@ -1158,8 +1158,9 @@ ulint
dict_index_get_nth_col_pos( dict_index_get_nth_col_pos(
/*=======================*/ /*=======================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n) /*!< in: column number */ ulint n, /*!< in: column number */
__attribute__((nonnull, warn_unused_result)); ulint* prefix_col_pos) /*!< out: col num if prefix */
__attribute__((nonnull(1), warn_unused_result));
/********************************************************************//** /********************************************************************//**
Looks for column n in an index. Looks for column n in an index.
@return position in internal representation of the index; @return position in internal representation of the index;
@@ -1170,9 +1171,11 @@ dict_index_get_nth_col_or_prefix_pos(
/*=================================*/ /*=================================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n, /*!< in: column number */ ulint n, /*!< in: column number */
ibool inc_prefix) /*!< in: TRUE=consider ibool inc_prefix, /*!< in: TRUE=consider
column prefixes too */ column prefixes too */
__attribute__((nonnull, warn_unused_result)); ulint* prefix_col_pos) /*!< out: col num if prefix */
__attribute__((nonnull(1), warn_unused_result));
/********************************************************************//** /********************************************************************//**
Returns TRUE if the index contains a column or a prefix of that column. Returns TRUE if the index contains a column or a prefix of that column.
@return TRUE if contains the column or its prefix */ @return TRUE if contains the column or its prefix */

9
storage/xtradb/include/dict0dict.ic
View File

@@ -1225,7 +1225,8 @@ dict_index_get_sys_col_pos(
} }
return(dict_index_get_nth_col_pos( return(dict_index_get_nth_col_pos(
index, dict_table_get_sys_col_no(index->table, type))); index, dict_table_get_sys_col_no(index->table, type),
NULL));
} }
/*********************************************************************//** /*********************************************************************//**
@@ -1277,9 +1278,11 @@ ulint
dict_index_get_nth_col_pos( dict_index_get_nth_col_pos(
/*=======================*/ /*=======================*/
const dict_index_t* index, /*!< in: index */ const dict_index_t* index, /*!< in: index */
ulint n) /*!< in: column number */ ulint n, /*!< in: column number */
ulint* prefix_col_pos) /*!< out: col num if prefix */
{ {
return(dict_index_get_nth_col_or_prefix_pos(index, n, FALSE)); return(dict_index_get_nth_col_or_prefix_pos(index, n, FALSE,
prefix_col_pos));
} }
#ifndef UNIV_HOTBACKUP #ifndef UNIV_HOTBACKUP

10
storage/xtradb/include/row0mysql.h
View File

@@ -606,6 +606,12 @@ struct mysql_row_templ_t {
Innobase record in the current index; Innobase record in the current index;
not defined if template_type is not defined if template_type is
ROW_MYSQL_WHOLE_ROW */ ROW_MYSQL_WHOLE_ROW */
ibool rec_field_is_prefix; /* is this field in a prefix index? */
ulint rec_prefix_field_no; /* record field, even if just a
prefix; same as rec_field_no when not a
prefix, otherwise rec_field_no is
ULINT_UNDEFINED but this is the true
field number*/
ulint clust_rec_field_no; /*!< field number of the column in an ulint clust_rec_field_no; /*!< field number of the column in an
Innobase record in the clustered index; Innobase record in the clustered index;
not defined if template_type is not defined if template_type is
@@ -708,7 +714,9 @@ struct row_prebuilt_t {
columns through a secondary index columns through a secondary index
and at least one column is not in and at least one column is not in
the secondary index, then this is the secondary index, then this is
set to TRUE */ set to TRUE; note that sometimes this
is set but we later optimize out the
clustered index lookup */
unsigned templ_contains_blob:1;/*!< TRUE if the template contains unsigned templ_contains_blob:1;/*!< TRUE if the template contains
a column with DATA_BLOB == a column with DATA_BLOB ==
get_innobase_type_from_mysql_type(); get_innobase_type_from_mysql_type();

2
storage/xtradb/include/srv0mon.h
View File

@@ -167,6 +167,8 @@ enum monitor_id_t {
MONITOR_OVLD_INDEX_PAGES_WRITTEN, MONITOR_OVLD_INDEX_PAGES_WRITTEN,
MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN, MONITOR_OVLD_NON_INDEX_PAGES_WRITTEN,
MONITOR_OVLD_PAGES_READ, MONITOR_OVLD_PAGES_READ,
MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS,
MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED,
MONITOR_OVLD_BYTE_READ, MONITOR_OVLD_BYTE_READ,
MONITOR_OVLD_BYTE_WRITTEN, MONITOR_OVLD_BYTE_WRITTEN,
MONITOR_FLUSH_BATCH_SCANNED, MONITOR_FLUSH_BATCH_SCANNED,

13
storage/xtradb/include/srv0srv.h
View File

@@ -158,6 +158,12 @@ struct srv_stats_t {
/** Number of rows inserted */ /** Number of rows inserted */
ulint_ctr_64_t n_rows_inserted; ulint_ctr_64_t n_rows_inserted;
/** Number of times secondary index lookup triggered cluster lookup */
ulint_ctr_64_t n_sec_rec_cluster_reads;
/** Number of times prefix optimization avoided triggering cluster lookup */
ulint_ctr_64_t n_sec_rec_cluster_reads_avoided;
ulint_ctr_1_t lock_deadlock_count; ulint_ctr_1_t lock_deadlock_count;
ulint_ctr_1_t n_lock_max_wait_time; ulint_ctr_1_t n_lock_max_wait_time;
@@ -326,6 +332,10 @@ extern ulong srv_auto_extend_increment;
extern ibool srv_created_new_raw; extern ibool srv_created_new_raw;
/* Optimize prefix index queries to skip cluster index lookup when possible */
/* Enables or disables this prefix optimization. Disabled by default. */
extern my_bool srv_prefix_index_cluster_optimization;
/** Maximum number of srv_n_log_files, or innodb_log_files_in_group */ /** Maximum number of srv_n_log_files, or innodb_log_files_in_group */
#define SRV_N_LOG_FILES_MAX 100 #define SRV_N_LOG_FILES_MAX 100
extern ulong srv_n_log_files; extern ulong srv_n_log_files;
@@ -1183,6 +1193,9 @@ struct export_var_t{
compression */ compression */
ib_int64_t innodb_pages_page_compression_error;/*!< Number of page ib_int64_t innodb_pages_page_compression_error;/*!< Number of page
compression errors */ compression errors */
ulint innodb_sec_rec_cluster_reads; /*!< srv_sec_rec_cluster_reads */
ulint innodb_sec_rec_cluster_reads_avoided; /*!< srv_sec_rec_cluster_reads_avoided */
}; };
/** Thread slot in the thread table. */ /** Thread slot in the thread table. */

6
storage/xtradb/pars/pars0opt.cc
View File

@@ -948,12 +948,14 @@ opt_find_all_cols(
/* Fill in the field_no fields in sym_node */ /* Fill in the field_no fields in sym_node */
sym_node->field_nos[SYM_CLUST_FIELD_NO] = dict_index_get_nth_col_pos( sym_node->field_nos[SYM_CLUST_FIELD_NO] = dict_index_get_nth_col_pos(
dict_table_get_first_index(index->table), sym_node->col_no); dict_table_get_first_index(index->table), sym_node->col_no,
NULL);
if (!dict_index_is_clust(index)) { if (!dict_index_is_clust(index)) {
ut_a(plan); ut_a(plan);
col_pos = dict_index_get_nth_col_pos(index, sym_node->col_no); col_pos = dict_index_get_nth_col_pos(index, sym_node->col_no,
NULL);
if (col_pos == ULINT_UNDEFINED) { if (col_pos == ULINT_UNDEFINED) {

3
storage/xtradb/pars/pars0pars.cc
View File

@@ -1232,7 +1232,8 @@ pars_process_assign_list(
col_sym = assign_node->col; col_sym = assign_node->col;
upd_field_set_field_no(upd_field, dict_index_get_nth_col_pos( upd_field_set_field_no(upd_field, dict_index_get_nth_col_pos(
clust_index, col_sym->col_no), clust_index, col_sym->col_no,
NULL),
clust_index, NULL); clust_index, NULL);
upd_field->exp = assign_node->val; upd_field->exp = assign_node->val;

74
storage/xtradb/row/row0sel.cc
View File

@@ -56,6 +56,7 @@ Created 12/19/1997 Heikki Tuuri
#include "row0mysql.h" #include "row0mysql.h"
#include "read0read.h" #include "read0read.h"
#include "buf0lru.h" #include "buf0lru.h"
#include "srv0srv.h"
#include "ha_prototypes.h" #include "ha_prototypes.h"
#include "srv0start.h" #include "srv0start.h"
#include "m_string.h" /* for my_sys.h */ #include "m_string.h" /* for my_sys.h */
@@ -2942,9 +2943,14 @@ row_sel_store_mysql_rec(
: templ->rec_field_no; : templ->rec_field_no;
/* We should never deliver column prefixes to MySQL, /* We should never deliver column prefixes to MySQL,
except for evaluating innobase_index_cond(). */ except for evaluating innobase_index_cond(). */
/* ...actually, we do want to do this in order to
support the prefix query optimization.
ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len ut_ad(dict_index_get_nth_field(index, field_no)->prefix_len
== 0); == 0);
...so we disable this assert. */
if (!row_sel_store_mysql_field(mysql_rec, prebuilt, if (!row_sel_store_mysql_field(mysql_rec, prebuilt,
rec, index, offsets, rec, index, offsets,
field_no, templ)) { field_no, templ)) {
@@ -3037,6 +3043,8 @@ row_sel_get_clust_rec_for_mysql(
dberr_t err; dberr_t err;
trx_t* trx; trx_t* trx;
srv_stats.n_sec_rec_cluster_reads.inc();
*out_rec = NULL; *out_rec = NULL;
trx = thr_get_trx(thr); trx = thr_get_trx(thr);
@@ -3693,6 +3701,7 @@ row_search_for_mysql(
ulint* offsets = offsets_; ulint* offsets = offsets_;
ibool table_lock_waited = FALSE; ibool table_lock_waited = FALSE;
byte* next_buf = 0; byte* next_buf = 0;
ibool use_clustered_index = FALSE;
rec_offs_init(offsets_); rec_offs_init(offsets_);
@@ -4727,10 +4736,69 @@ locks_ok:
} }
/* Get the clustered index record if needed, if we did not do the /* Get the clustered index record if needed, if we did not do the
search using the clustered index. */ search using the clustered index... */
use_clustered_index =
(index != clust_index && prebuilt->need_to_access_clustered);
if (use_clustered_index && srv_prefix_index_cluster_optimization
&& prebuilt->n_template <= index->n_fields) {
/* ...but, perhaps avoid the clustered index lookup if
all of the following are true:
1) all columns are in the secondary index
2) all values for columns that are prefix-only
indexes are shorter than the prefix size
This optimization can avoid many IOs for certain schemas.
*/
ibool row_contains_all_values = TRUE;
int i;
for (i = 0; i < prebuilt->n_template; i++) {
/* Condition (1) from above: is the field in the
index (prefix or not)? */
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
ulint secondary_index_field_no =
templ->rec_prefix_field_no;
if (secondary_index_field_no == ULINT_UNDEFINED) {
row_contains_all_values = FALSE;
break;
}
/* Condition (2) from above: if this is a
prefix, is this row's value size shorter
than the prefix? */
if (templ->rec_field_is_prefix) {
ulint record_size = rec_offs_nth_size(
offsets,
secondary_index_field_no);
const dict_field_t *field =
dict_index_get_nth_field(
index,
secondary_index_field_no);
ut_a(field->prefix_len > 0);
if (record_size >= field->prefix_len) {
row_contains_all_values = FALSE;
break;
}
}
}
/* If (1) and (2) were true for all columns above, use
rec_prefix_field_no instead of rec_field_no, and skip
the clustered lookup below. */
if (row_contains_all_values) {
for (i = 0; i < prebuilt->n_template; i++) {
mysql_row_templ_t* templ =
prebuilt->mysql_template + i;
templ->rec_field_no =
templ->rec_prefix_field_no;
ut_a(templ->rec_field_no != ULINT_UNDEFINED);
}
use_clustered_index = FALSE;
srv_stats.n_sec_rec_cluster_reads_avoided.inc();
}
}
if (use_clustered_index) {
if (index != clust_index && prebuilt->need_to_access_clustered) {
requires_clust_rec: requires_clust_rec:
ut_ad(index != clust_index); ut_ad(index != clust_index);
/* We use a 'goto' to the preceding label if a consistent /* We use a 'goto' to the preceding label if a consistent

22
storage/xtradb/srv/srv0mon.cc
View File

@@ -309,6 +309,18 @@ static monitor_info_t innodb_counter_info[] =
MONITOR_EXISTING | MONITOR_DEFAULT_ON), MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_PAGES_READ}, MONITOR_DEFAULT_START, MONITOR_OVLD_PAGES_READ},
{"buffer_index_sec_rec_cluster_reads", "buffer",
"Number of secondary record reads triggered cluster read",
static_cast<monitor_type_t>(
MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS},
{"buffer_index_sec_rec_cluster_reads_avoided", "buffer",
"Number of secondary record reads avoided triggering cluster read",
static_cast<monitor_type_t>(
MONITOR_EXISTING | MONITOR_DEFAULT_ON),
MONITOR_DEFAULT_START, MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED},
{"buffer_data_reads", "buffer", {"buffer_data_reads", "buffer",
"Amount of data read in bytes (innodb_data_reads)", "Amount of data read in bytes (innodb_data_reads)",
static_cast<monitor_type_t>( static_cast<monitor_type_t>(
@@ -1646,6 +1658,16 @@ srv_mon_process_existing_counter(
value = stat.n_pages_read; value = stat.n_pages_read;
break; break;
/* Number of times secondary index lookup triggered cluster lookup */
case MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS:
value = srv_stats.n_sec_rec_cluster_reads;
break;
/* Number of times prefix optimization avoided triggering cluster
lookup */
case MONITOR_OVLD_INDEX_SEC_REC_CLUSTER_READS_AVOIDED:
value = srv_stats.n_sec_rec_cluster_reads_avoided;
break;
/* innodb_data_reads, the total number of data reads */ /* innodb_data_reads, the total number of data reads */
case MONITOR_OVLD_BYTE_READ: case MONITOR_OVLD_BYTE_READ:
value = srv_stats.data_read; value = srv_stats.data_read;

9
storage/xtradb/srv/srv0srv.cc
View File

@@ -490,6 +490,10 @@ UNIV_INTERN ulint srv_fast_shutdown = 0;
/* Generate a innodb_status.<pid> file */ /* Generate a innodb_status.<pid> file */
UNIV_INTERN ibool srv_innodb_status = FALSE; UNIV_INTERN ibool srv_innodb_status = FALSE;
/* Optimize prefix index queries to skip cluster index lookup when possible */
/* Enables or disables this prefix optimization. Disabled by default. */
UNIV_INTERN my_bool srv_prefix_index_cluster_optimization = 0;
/* When estimating number of different key values in an index, sample /* When estimating number of different key values in an index, sample
this many index pages, there are 2 ways to calculate statistics: this many index pages, there are 2 ways to calculate statistics:
* persistent stats that are calculated by ANALYZE TABLE and saved * persistent stats that are calculated by ANALYZE TABLE and saved
@@ -1960,6 +1964,11 @@ srv_export_innodb_status(void)
} }
#endif /* UNIV_DEBUG */ #endif /* UNIV_DEBUG */
export_vars.innodb_sec_rec_cluster_reads =
srv_stats.n_sec_rec_cluster_reads;
export_vars.innodb_sec_rec_cluster_reads_avoided =
srv_stats.n_sec_rec_cluster_reads_avoided;
mutex_exit(&srv_innodb_monitor_mutex); mutex_exit(&srv_innodb_monitor_mutex);
} }

3
storage/xtradb/trx/trx0rec.cc
View File

@@ -781,7 +781,8 @@ trx_undo_page_report_modify(
} }
pos = dict_index_get_nth_col_pos(index, pos = dict_index_get_nth_col_pos(index,
col_no); col_no,
NULL);
ptr += mach_write_compressed(ptr, pos); ptr += mach_write_compressed(ptr, pos);
/* Save the old value of field */ /* Save the old value of field */