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699291a8e6
- Make the range-et-al optimizer produce E(#table records after table
condition is applied),
- Make the join optimizer use this value,
- Add "filtered" column to EXPLAIN EXTENDED to show
fraction of records left after table condition is applied
- Adjust test results, add comments
24 lines
1.2 KiB
Plaintext
24 lines
1.2 KiB
Plaintext
drop table if exists t1,t2;
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create table t1(str varchar(10) default 'def',strnull varchar(10),intg int default '10',rel double default '3.14');
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insert into t1 values ('','',0,0.0);
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select default(str), default(strnull), default(intg), default(rel) from t1;
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default(str) default(strnull) default(intg) default(rel)
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def NULL 10 3.14
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explain extended select default(str), default(strnull), default(intg), default(rel) from t1;
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id select_type table type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00
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Warnings:
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Note 1003 select default(`test`.`t1`.`str`) AS `default(str)`,default(`test`.`t1`.`strnull`) AS `default(strnull)`,default(`test`.`t1`.`intg`) AS `default(intg)`,default(`test`.`t1`.`rel`) AS `default(rel)` from `test`.`t1`
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select * from t1 where str <> default(str);
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str strnull intg rel
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0 0
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explain select * from t1 where str <> default(str);
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id select_type table type possible_keys key key_len ref rows Extra
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1 SIMPLE t1 system NULL NULL NULL NULL 1
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drop table t1;
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CREATE TABLE t1 (id int(11), s varchar(20));
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INSERT INTO t1 VALUES (1, 'one'), (2, 'two'), (3, 'three');
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SELECT s, 32 AS mi FROM t1 GROUP BY s HAVING DEFAULT(mi) IS NULL;
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ERROR HY000: Field 'mi' doesn't have a default value
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DROP TABLE t1;
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