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9cd4d49840
"rows examined" estimates". This change implements "innodb_stats_method"
with options of "nulls_equal", "nulls_unequal" and "null_ignored".
rb://553 approved by Marko
96 lines
3.0 KiB
Plaintext
96 lines
3.0 KiB
Plaintext
set global innodb_stats_method = default;
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select @@innodb_stats_method;
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@@innodb_stats_method
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nulls_equal
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select count(*) from bug30243_3 where org_id is not NULL;
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count(*)
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20
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select count(*) from bug30243_3 where org_id is NULL;
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count(*)
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16384
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select count(*) from bug30243_2 where org_id is not NULL;
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count(*)
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224
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select count(*) from bug30243_2 where org_id is NULL;
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count(*)
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65536
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select @@innodb_stats_method;
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@@innodb_stats_method
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nulls_equal
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analyze table bug30243_1;
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Table Op Msg_type Msg_text
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test.bug30243_1 analyze status OK
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analyze table bug30243_2;
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Table Op Msg_type Msg_text
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test.bug30243_2 analyze status OK
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analyze table bug30243_3;
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Table Op Msg_type Msg_text
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test.bug30243_3 analyze status OK
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set global innodb_stats_method = "NULL";
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ERROR 42000: Variable 'stats_method' can't be set to the value of 'NULL'
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set global innodb_stats_method = "nulls_ignored";
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select @@innodb_stats_method;
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@@innodb_stats_method
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nulls_ignored
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analyze table bug30243_1;
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Table Op Msg_type Msg_text
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test.bug30243_1 analyze status OK
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analyze table bug30243_2;
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Table Op Msg_type Msg_text
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test.bug30243_2 analyze status OK
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analyze table bug30243_3;
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Table Op Msg_type Msg_text
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test.bug30243_3 analyze status OK
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explain SELECT COUNT(*), 0
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FROM bug30243_1 orgs
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LEFT JOIN bug30243_3 sa_opportunities
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ON orgs.org_id=sa_opportunities.org_id
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LEFT JOIN bug30243_2 contacts
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ON orgs.org_id=contacts.org_id ;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE orgs index NULL org_id 4 NULL 128 Using index
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1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id 1 Using index
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1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id 1 Using index
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select @@innodb_stats_method;
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@@innodb_stats_method
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nulls_ignored
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set global innodb_stats_method = "nulls_unequal";
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select @@innodb_stats_method;
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@@innodb_stats_method
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nulls_unequal
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analyze table bug30243_1;
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Table Op Msg_type Msg_text
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test.bug30243_1 analyze status OK
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analyze table bug30243_2;
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Table Op Msg_type Msg_text
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test.bug30243_2 analyze status OK
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analyze table bug30243_3;
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Table Op Msg_type Msg_text
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test.bug30243_3 analyze status OK
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explain SELECT COUNT(*), 0
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FROM bug30243_1 orgs
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LEFT JOIN bug30243_3 sa_opportunities
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ON orgs.org_id=sa_opportunities.org_id
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LEFT JOIN bug30243_2 contacts
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ON orgs.org_id=contacts.org_id;
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE orgs index NULL org_id 4 NULL 128 Using index
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1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id 1 Using index
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1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id 1 Using index
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SELECT COUNT(*) FROM table_bug30423 WHERE org_id IS NULL;
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COUNT(*)
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1024
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set global innodb_stats_method = "nulls_unequal";
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analyze table table_bug30423;
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Table Op Msg_type Msg_text
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test.table_bug30423 analyze status OK
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set global innodb_stats_method = "nulls_ignored";
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analyze table table_bug30423;
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Table Op Msg_type Msg_text
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test.table_bug30423 analyze status OK
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set global innodb_stats_method = nulls_equal;
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drop table bug30243_2;
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drop table bug30243_1;
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drop table bug30243_3;
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drop table table_bug30423;
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