I just added another index to a table in my database but now the site is crashing, queries get locked and not unlocked and queries are not executed (I can see them in the process list and they usually take less than a second to execute but now they are at around 600 seconds and more etc.).
I didn't change anything on my site, just added an index. How is this possible, did anybody had similiar issues before that might help me solve my issue?
Update: I'm not really sure what happened, but one specific query was really slow after adding the index (even though this index wasn't needed/used for this specific query). Even removing the index didn't help to speed the query up again. After that I removed all indizes from this table and added the indizes again one by one, after doing that the query was fast again. Not sure if this helps anybody but this fixed it for me.