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Displaying posts with tag: timer (reset)
Timing queries in the 21st century (with LD_PRELOAD and sed)

So… Baron blogged about wanting higher precision timers from the mysql binary and that running sed on the binary wasn’t cutting it. However… I am not one to give up that easily!

This is what LD_PRELOAD was made for! Evil nasty hacks to make your life easier!

By looking at the source code, I can easily work out how this works… I just have to override two calls! They being sysconf() (we fake how many ticks per second there are) and times() (let’s return a much higher precision number).

Combined with the sed hack on the binary to change the sprintf call to print out the higher precision number, we have:

mysql> select count(*) from t1;
| count(*) |
|   710720 |
1 row in set (1.080110 sec)

Get it from my junkcode: …

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