It's used as an archive of events and data. The data are written just once and then read multiple times.

I think that the response times are limited by the disk speed and that indexing for lookups works in a similar way on both MyISAM and InnoDB. We were considering upgrading it to Aria storage engine, as it offers better consistency (after a crash - I have read that somewhere), but it's not much time to do it now.

Could be the upgrade might be easier when we will have a DB-proxy in place.

On Thu, 5 Aug 2021 at 10:14, Gordan Bobic <gordan.bobic@gmail.com> wrote:

I think you are going to have to bite the bullet on conversion to InnoDB sooner rather than later. The performance improvement you are going to see will likely be orders of magnitude. The longer you leave it, the more painful it is going to become.
You could do it on a slave and then promote it, or you could do it with pt-online-schema-change.
While MyISAM still has some very narrow niche uses, it really is way past time to retire it in any regular use.