I have a 768M tmpfs dir that I use for mysql temp directory. It occasional fills up when running reports on large date ranges. When this happen the report fails and I get an error 28.
This actually seems acceptable to me because it prevents a query from running too long and put load on the server. (I think)
The advantage to using tmpfs is queries that use temporary tables run 50% faster.
My question is: is the tmpfs fills up while an insert or replace into is running will this fail?
Also it seems that when mysql fills the directory up the files are then deleted when the query fails. Will there ever be a case where it doesn't?
Do you think I could cause any issues using /tmp for MySQL temp dir? I have about 50 concurrent connections but not all of them are running reports at once.
What are the pros and cons of not using tmpfs?