All I was trying to achieve is to limit I/O rate done by pg_dump.
The script is a very simple pipe rate limitter and nothing more:
it reads input, but outputs data no more than at rate specified.
I guess it helps because even if pg_dump outputs data at 20 mb/sec,
the script won't be able to read it at rate higher than output rate. Pipe
buffer is not infinitive, so pg_dump output rate and hard disk reads become
almost equal the input rate of my perl script.
On Wed, 25 Jan 2006 11:21:58 -0500
Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Years ago there was some experimentation with dump-rate throttling logic
> inside pg_dump itself --- there's still a comment about it in pg_dump.c.
> The experiment didn't seem very successful, which is why it never got to
> be a permanent feature. I'm curious to know why this perl script is
> doing a better job than we were able to do inside pg_dump.
--
Evgeny Gridasov
Software Engineer
I-Free, Russia