Re: Re: Hot Standby query cancellation and Streaming Replication integration

[Dimitri Fontaine <dfontaine(at)hi-media(dot)com>]

Josh Berkus <josh(at)agliodbs(dot)com> writes:
> 2) A more usable vacuum_defer_cleanup_age.  If it was feasible for a
> user to configure the master to not vacuum records less than, say, 5
> minutes dead, then that would again offer the choice to the user of
> slightly degraded performance on the master (acceptable) vs. lots of
> query cancel (unacceptable).  I'm going to test Greg's case with
> vacuum_cleanup_age used fairly liberally to see if this approach has
> merit.

I think that to associate any time based interval notion with the XID
flow, you need a ticker. We already took the txid and txid_snapshot
types and functions from Skytools, which took them from Slony.

Maybe we could consider borrowing pgqd, the C version of the ticker, for
being able to specify in human time how long a dead transaction is
allowed to remain in the heap?

  http://github.com/markokr/skytools-dev/tree/master/sql/ticker/

Regards,
-- 
dim