mirror of
https://github.com/MariaDB/server.git
synced 2025-02-07 06:12:18 +01:00
727491b72a
This includes all test changes from
"Changing all cost calculation to be given in milliseconds"
and forwards.
Some of the things that caused changes in the result files:
- As part of fixing tests, I added 'echo' to some comments to be able to
easier find out where things where wrong.
- MATERIALIZED has now a higher cost compared to X than before. Because
of this some MATERIALIZED types have changed to DEPENDEND SUBQUERY.
- Some test cases that required MATERIALIZED to repeat a bug was
changed by adding more rows to force MATERIALIZED to happen.
- 'Filtered' in SHOW EXPLAIN has in many case changed from 100.00 to
something smaller. This is because now filtered also takes into
account the smallest possible ref access and filters, even if they
where not used. Another reason for 'Filtered' being smaller is that
we now also take into account implicit filtering done for subqueries
using FIRSTMATCH.
(main.subselect_no_exists_to_in)
This is caluculated in best_access_path() and stored in records_out.
- Table orders has changed because more accurate costs.
- 'index' and 'ALL' for small tables has changed to use 'range' or
'ref' because of optimizer_scan_setup_cost.
- index can be changed to 'range' as 'range' optimizer assumes we don't
have to read the blocks from disk that range optimizer has already read.
This can be confusing in the case where there is no obvious where clause
but instead there is a hidden 'key_column > NULL' added by the optimizer.
(main.subselect_no_exists_to_in)
- Scan on primary clustered key does not report 'Using Index' anymore
(It's a table scan, not an index scan).
- For derived tables, the number of rows is now 100 instead of 2,
which can be seen in EXPLAIN.
- More tests have "Using index for group by" as the cost of this
optimization is now more correct (lower).
- A primary key could be preferred for a normal key, even if it would
access more rows, as it's faster to do 1 lokoup and 3 'index_next' on a
clustered primary key than one lookup trough a secondary.
(main.stat_tables_innodb)
Notes:
- There was a 4.7% more calls to best_extension_by_limited_search() in
the main.greedy_optimizer test. However examining the test results
it looked that the plans where slightly better (eq_ref where more
chained together) so I assume this is ok.
- I have verified a few test cases where there was notable/unexpected
changes in the plan and in all cases the new optimizer plans where
faster. (main.greedy_optimizer and some others)
106 lines
3.8 KiB
Text
106 lines
3.8 KiB
Text
set global innodb_stats_method = default;
|
|
select @@innodb_stats_method;
|
|
@@innodb_stats_method
|
|
nulls_equal
|
|
select count(*) from bug30243_3 where org_id is not NULL;
|
|
count(*)
|
|
20
|
|
select count(*) from bug30243_3 where org_id is NULL;
|
|
count(*)
|
|
16384
|
|
select count(*) from bug30243_2 where org_id is not NULL;
|
|
count(*)
|
|
224
|
|
select count(*) from bug30243_2 where org_id is NULL;
|
|
count(*)
|
|
65536
|
|
select @@innodb_stats_method;
|
|
@@innodb_stats_method
|
|
nulls_equal
|
|
analyze table bug30243_1;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_1 analyze status Engine-independent statistics collected
|
|
test.bug30243_1 analyze status OK
|
|
analyze table bug30243_2;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_2 analyze status Engine-independent statistics collected
|
|
test.bug30243_2 analyze status OK
|
|
analyze table bug30243_3;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_3 analyze status Engine-independent statistics collected
|
|
test.bug30243_3 analyze status OK
|
|
set global innodb_stats_method = "NULL";
|
|
ERROR 42000: Variable 'innodb_stats_method' can't be set to the value of 'NULL'
|
|
set global innodb_stats_method = "nulls_ignored";
|
|
select @@innodb_stats_method;
|
|
@@innodb_stats_method
|
|
nulls_ignored
|
|
analyze table bug30243_1;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_1 analyze status Engine-independent statistics collected
|
|
test.bug30243_1 analyze status OK
|
|
analyze table bug30243_2;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_2 analyze status Engine-independent statistics collected
|
|
test.bug30243_2 analyze status OK
|
|
analyze table bug30243_3;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_3 analyze status Engine-independent statistics collected
|
|
test.bug30243_3 analyze status OK
|
|
explain SELECT COUNT(*), 0
|
|
FROM bug30243_1 orgs
|
|
LEFT JOIN bug30243_3 sa_opportunities
|
|
ON orgs.org_id=sa_opportunities.org_id
|
|
LEFT JOIN bug30243_2 contacts
|
|
ON orgs.org_id=contacts.org_id ;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE orgs ALL NULL NULL NULL NULL ROWS
|
|
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id ROWS Using index
|
|
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id ROWS Using index
|
|
select @@innodb_stats_method;
|
|
@@innodb_stats_method
|
|
nulls_ignored
|
|
set global innodb_stats_method = "nulls_unequal";
|
|
select @@innodb_stats_method;
|
|
@@innodb_stats_method
|
|
nulls_unequal
|
|
analyze table bug30243_1;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_1 analyze status Engine-independent statistics collected
|
|
test.bug30243_1 analyze status OK
|
|
analyze table bug30243_2;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_2 analyze status Engine-independent statistics collected
|
|
test.bug30243_2 analyze status OK
|
|
analyze table bug30243_3;
|
|
Table Op Msg_type Msg_text
|
|
test.bug30243_3 analyze status Engine-independent statistics collected
|
|
test.bug30243_3 analyze status OK
|
|
explain SELECT COUNT(*), 0
|
|
FROM bug30243_1 orgs
|
|
LEFT JOIN bug30243_3 sa_opportunities
|
|
ON orgs.org_id=sa_opportunities.org_id
|
|
LEFT JOIN bug30243_2 contacts
|
|
ON orgs.org_id=contacts.org_id;
|
|
id select_type table type possible_keys key key_len ref rows Extra
|
|
1 SIMPLE orgs ALL NULL NULL NULL NULL ROWS
|
|
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id ROWS Using index
|
|
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id ROWS Using index
|
|
SELECT COUNT(*) FROM table_bug30423 WHERE org_id IS NULL;
|
|
COUNT(*)
|
|
1024
|
|
set global innodb_stats_method = "nulls_unequal";
|
|
analyze table table_bug30423;
|
|
Table Op Msg_type Msg_text
|
|
test.table_bug30423 analyze status Engine-independent statistics collected
|
|
test.table_bug30423 analyze status OK
|
|
set global innodb_stats_method = "nulls_ignored";
|
|
analyze table table_bug30423;
|
|
Table Op Msg_type Msg_text
|
|
test.table_bug30423 analyze status Engine-independent statistics collected
|
|
test.table_bug30423 analyze status OK
|
|
set global innodb_stats_method = nulls_equal;
|
|
drop table bug30243_2;
|
|
drop table bug30243_1;
|
|
drop table bug30243_3;
|
|
drop table table_bug30423;
|