Re: How to handle secondary keys in partitioning?

[Mattias Jonsson]

partitioning can help concurrent insert/updates due to decreased lock contentions (locks are spread out on more than one table/partition).

I have added a comment to datacharmer's blog since it could easily be misunderstood.

So NO partitioning does not add any additional locking, but the current problem is that MySQL does open and lock tables before optimizing, and pruning is a very early step of the optimization. This leads to all partitions have to be opened and locked even if a lot of them can be pruned away. If an engine uses row-level locks (like InnoDB) it will still use the same type of locks (inside each partition) if it is partitioned.