Mashiah Davidson mashiah.davidson@gmail.com wrote:
Once again, a question on query killer. Below its report informs that with near-zero replag a very simple count(*) only query on s6 takes too long, and the killer expects SLOW_OK would help.
I think something is wrong fundamentally once such a query takes that long, and there is no reason to add SLOW_OK and wait even longer.
[...]
SELECT count(*) INTO @tl_count FROM ruwiki_p.templatelinks
[...]
I don't know about MySQL, but usually "COUNT" is rather slow as it has to look up for every row if it is visible to the current transaction.
When did you start using it? :-)
Tim