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Fix Bug#30423 "InnoDBs treatment of NULL in index stats causes bad

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"rows examined" estimates". This change implements "innodb_stats_method"
with options of "nulls_equal", "nulls_unequal" and "null_ignored".
      
rb://553 approved by Marko
This commit is contained in:
Jimmy Yang
2011-01-14 09:02:28 -08:00
parent 634fe86056
commit 9cd4d49840
25 changed files with 1157 additions and 77 deletions
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95
mysql-test/suite/innodb_plugin/r/innodb_bug30423.result Normal file
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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 OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
test.bug30243_3 analyze status OK
set global innodb_stats_method = "NULL";
ERROR 42000: Variable '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 OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
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 index NULL org_id 4 NULL 128 Using index
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id 1 Using index
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id 1 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 OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
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 index NULL org_id 4 NULL 128 Using index
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id 1 Using index
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id 1 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 OK
set global innodb_stats_method = "nulls_ignored";
analyze table table_bug30423;
Table Op Msg_type Msg_text
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;