How to keep a php script from timing out because of a long mysql query

Question

I have an update query being run by a cron task that's timing out. The query takes, on average, five minutes to execute when executed in navicat.

The code looks roughly like this. It's quite simple:

// $db is a mysqli link
set_time_limit (0); // should keep the script from timing out
$query = "SLOW QUERY";
$result = $db->query($query);
if (!$result)
    echo "error";

Even though the script shouldn't timeout, the time spent waiting on the sql call still seems to be subject to a timeout.

Is there an asynchronous call that can be used? Or adjust the timeout?

Is the timeout different because it's being called from the command line rather than through Apache?

Thanks

Answer 1

According to the manual:

Note: The set_time_limit() function and the configuration directive max_execution_time only affect the execution time of the script itself. Any time spent on activity that happens outside the execution of the script such as system calls using system(), stream operations, database queries, etc. is not included when determining the maximum time that the script has been running.

So it's unlikely to have anything to do with PHP's time limit. What message are you getting when it times out? Perhaps there's a MySQL setting involved.

Answer 2

I had the same problem somwhere, and "solved" it with the following code (first two lines of my file):

set_time_limit(0);
ignore_user_abort(1);