tag:blogger.com,1999:blog-3080615211468083537.post3336697174209856356..comments2023-09-27T11:36:08.392+03:00Comments on Blog of (former?) MySQL Entomologist: Fun with Bugs #96 - On MySQL Bug Reports I am Subscribed to, Part XXXValerii Kravchukhttp://www.blogger.com/profile/13158916419325454260noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-3080615211468083537.post-87523952793233331752020-04-05T08:02:04.846+03:002020-04-05T08:02:04.846+03:00Hi Valerii!
I think you are jumping to conclusion...Hi Valerii!<br /><br />I think you are jumping to conclusions when you are saying "Make sure to use internal_tmp_mem_storage_engine=MEMORY if you care about performance." Even if the performance was a little bit better with MEMORY in the case I reported, there are lot of cases where TempTable would be a better choice:<br /><br />1. MEMORY will often require much more memory since it does not support variable length rows.<br />2. MEMORY does not support BLOB, TEXT, JSON and GEOMETRY types, so internal temporary tables with such columns will have to be stored in a disk-based engine.<br />3. AFAIU, MEMORY will allocate the max temp table size up front even for small temp tables.<br />4. TempTable give you better control over the total memory usage since all connections share a common memory area.Øysteinhttps://www.blogger.com/profile/11287151295676613909noreply@blogger.com