SmartReceipt/pg_rollingwindow — pull request #3 by ahammond (2012-05-15 22:48:30+00:00)
Title: pre-execute and post-execute hooks

Some of the actions taken by pg_rollingwindows can require very heavy
locks (AccessExclusive, for example). This adds a way to execute a
command before and after pg_rollingwindows does things.

If the pre-execute command fails, then the rolling_windows verb will not
be executed and neither will the post-execute command.

Even if the rolling_windows verb fails, the post-execute command will be
executed.

If pre/post execute is used in conjunction with the --every_n_seconds
parameter, pre/post commands will be executed before and after every
instance of the verb being executed every-n-seconds.