Comments on: Update Delayed on Mysql and PHP

By: John Millington

John Millington — Thu, 15 Apr 2010 18:26:40 +0000

I think this is a great idea and I’m gonna try it out. Tired of seeing a bunch of stuff which doesn’t really even matter to the user, on my show processlist

By: frank

frank — Thu, 02 Apr 2009 18:52:17 +0000

No, this is to mimic a Mysql query queue by using apache threads as a queue. Presumably, when the script processing is shutting down, all your output to the browser has been sent. But the script will run the update_delayed function which will wait until mysql sees that the table is no longer being locked by any other higher priority queries. Apache will then keep that process until that happens or if timeout setting has reached. Therefore, it is also crucial to set_time_limit on your script to something higher than your maximum expected congestion time. If not, your script might timeout while waiting for mysql and your update will never happen.

This is certainly a hack. It would be much nicer if mysql implemented UPDATE DELAYED.

By: Chris Abbott

Chris Abbott — Thu, 02 Apr 2009 11:29:08 +0000

… and this doesn’t wait MySQL to return a result (i.e. behaves exactly the same to PHP as “insert delayed”? If so, that’s awfully clever.