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Problem:- If we create table using myisam/aria then this crashes the server. CREATE TABLE t1(a bit(1), b int auto_increment , index(a,b)); insert into t1 values(1,1); Or this query CREATE TABLE t1 (b BIT(1), pk INTEGER AUTO_INCREMENT PRIMARY KEY); ALTER TABLE t1 ADD INDEX(b,pk); INSERT INTO t1 VALUES (1,b'1'); ALTER TABLE t1 DROP PRIMARY KEY; Reason:- The reason for this is 1st- find_ref_key() finds what key an auto_increment field belongs to by comparing key_part->offset and field->ptr. But BIT fields might have zero length in the record, so a key might have many key parts with the same offset. That is, comparing offsets cannot uniquely identify the correct key part. 2nd- Since next_number_key_offset is zero it myisam/aria will think that auto_increment is in first part of key. 3nd- myisam/aria will call retrieve_auto_key which will see first key_part field as a bit field and call assert(0) Solution:- Many key parts might have the same offset, but BIT fields do not support auto_increment. So, we can skip all key parts over BIT fields, and then comparing offsets will be unambiguous.
27 lines
1.1 KiB
Text
27 lines
1.1 KiB
Text
create table t1(a bit(1), b int auto_increment ,id int, index(a,b));
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insert into t1 values(1,null,1);
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insert into t1 values(1,null,2);
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insert into t1 values(0,null,3);
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insert into t1 values(0,null,4);
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select a+0, b as auto_increment , id from t1 order by id;
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drop table t1;
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create table t1(a int auto_increment, b bit(5) ,id int, index (b,a));
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insert into t1 values(null,b'1',1);
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insert into t1 values(null,b'1',2);
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insert into t1 values(null,b'11',3);
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insert into t1 values(null,b'11',4);
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select a as auto_increment, b+0, id from t1 order by id;
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drop table t1;
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create table t1(a bit(1), b int auto_increment , c bit(1) , d bit(1), id int,index(a,c,b,d));
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insert into t1 values(1,null,1,1,1);
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insert into t1 values(1,null,1,1,2);
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insert into t1 values(0,null,1,1,3);
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insert into t1 values(1,null,0,1,4);
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select a+0, b as auto_increment, c+0, d+0, id from t1 order by id;
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drop table t1;
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CREATE TABLE t1 (b BIT(1), pk INTEGER AUTO_INCREMENT PRIMARY KEY);
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ALTER TABLE t1 ADD INDEX(b,pk);
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INSERT INTO t1 VALUES (1,b'1');
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ALTER TABLE t1 DROP PRIMARY KEY;
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select b+0, pk as auto_increment from t1;
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DROP TABLE t1;
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