On 2016-03-11 23:53:15 +0300, Vladimir Borodin wrote:
It was many times stated in threads about waits monitoring [0, 1, 2]
and supported by different people, but ultimately waits information
was stored in PgBackendStatus.
Only that it isn't. It's stored in PGPROC.
Sorry, I missed that. So monitoring of wait events for auxiliary processes still could be implemented?
This criticism is true of
the progress reporting patch, but a quick scan of the thread doesn't
show authors of the wait events patch participating there.
Can’t we think one more time about implementation provided by Ildus
and Alexander here [3]?
I don't think so. Afaics the proposed patch tried to do too many things
at once, and it's authors didn't listen well to criticism. Trying to go
back to that seems like a surefire way to have nothing in 9.6.
The idea is not to try implement all that at once (and more in 9.6) but give an ability to implement all that features eventually. If it is still possible, it’s great.
Seems that current implementation doesn’t give reasonable ways to
implement all that features and it is really sad.
Why is that?
Storing information about wait event in 4 bytes gives an ability to store only wait type and event. No way to store duration or extra information (i.e. buffer number for I/O events or buffer manager LWLocks). Maybe I’m missing something...
Andres Freund
--
May the force be with you…