maria-discuss team mailing list archive

["Ling, Andy" <Andy.Ling@xxxxxxxxxxxxxxx>]

I'm using MariDB 10.4.12 on Windows server 2016

I have a table with one of the columns defined as

`id` bigint(20) NOT NULL AUTO_INCREMENT

and

PRIMARY KEY (`id`)

It is currently a MyISAM table and has been in use for ages. The current auto increment value is AUTO_INCREMENT=106274948879084. Rows have been added and removed over time such that there are gaps in the id value. The table passes all checks, so there are no duplicate entries.

I recently tried to change the table to use the Aria engine using the command

ALTER TABLE xxx ENGINE=ARIA;

and got the error

ERROR 1062 (23000) at line 4: ALTER TABLE causes auto_increment resequencing, resulting in duplicate entry '106274948781020' for key 'PRIMARY'

I can fix the problem by resetting the auto increment values using

ALTER TABLE xxx AUTO_INCREMENT=1;

but is this something I should expect? First, I don't really see why it is resequencing. No data should be changing. Then why is the resequencing generating a duplicate entry? Fortunately in this instance I don't care what the id is, but had this been used by another table, changing the id may have caused problems.

Thanks for any help on this.

Andy Ling

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