Code review comment for lp:~sergei.glushchenko/percona-xtrabackup/2.1-xb-bug1240352

Revision history for this message
Sergei Glushchenko (sergei.glushchenko) wrote :

Alexey,

From http://dev.mysql.com/doc/refman/5.1/en/concurrent-inserts.html

The MyISAM storage engine supports concurrent inserts to reduce contention between readers and writers for a given table: If a MyISAM table has no holes in the data file (deleted rows in the middle), an INSERT statement can be executed to add rows to the end of the table at the same time that SELECT statements are reading rows from the table. If there are multiple INSERT statements, they are queued and performed in sequence, concurrently with the SELECT statements. The results of a concurrent INSERT may not be visible immediately.

In practice I saw many time that appended records to MyISAM tables are not visible by SELECT immediately. I think that FLUSH TABLE can help with it, but I am not sure.

« Back to merge proposal