… which was had data merged into it with INSERT ON DUPLICATE KEY UPDATE statements. The performance was extremely slow. I turned out it is caused by… case with just insert. The difference grows even larger if we remove index on column C – the “UPDATE” part of INSERT ON DUPLICATE KEY UPDATE completes in 22…
Comment: Why MySQL could be slow with large tables ?
September 24, 2008 By 139 Comments
…, id2, cnt) (where the pair id1, id2 forms the primary key) using INSERT … ON DUPLICATE KEY UPDATE cnt = cnt + 1. Obviously, the resulting table becomes large…. 200M rows for 300K lists), and I noticed that inserts become really slow. I guess this is due to index maintenance. Therefore…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… 1 Duplicates: 0 Warnings: 0 . . . mysql> INSERT …updating indexes took 18 seconds, and about the same time was spent on…by a slow tmpdir, …keys that are part of a FOREIGN KEY constraint; mysqldump –innodb-optimize-keys ignores foreign keys because InnoDB requires a full table rebuild on foreign key…
