Re: max_standby_delay considered harmful

On Tue, 2010-05-04 at 13:00 -0400, Bruce Momjian wrote:

> Well, this is kind of my point --- that if few people are going to need
> a parameter and it is going to take us to tell them to use it, it isn't
> a good parameter because the other 99.9% are going to stare at the
> parameters and not konw what it does or how it is different from other
> similar parameters. Adding another parameter might help 0.1% of our
> users, but it is going to confuse the other 99.9%. :-(

You've missed my point. Most users of HS will need these parameters.
There is no need to understand them immediately, nor do I expect them to
do so. People won't understand why they exist until they've understood
the actual behaviour, received some errors and *then* they will
understand them, want them and need them. Just like deadlocks, ndistinct
and loads of other features we provide and support.

The current behaviour of max_standby_delay is designed to favour High
Availability users, not query users. I doubt that users with HA concerns
are only 0.1% of our users. I've accepted that some users may not put
that consideration first and so adding some minor, easy to implement
additional parameters will improve the behaviour for those people.
Forcing just one behaviour will be bad for many people.

--
Simon Riggs www.2ndQuadrant.com