Re: Deprecating non-select rules (was Re: Last gasp)

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@2ndquadrant.com>
Cc: Noah Misch <noah@leadboat.com>, pgsql-hackers@postgresql.org
Date: 2012-04-10T13:46:45Z
Lists: pgsql-hackers
Andres Freund <andres@2ndquadrant.com> writes:
> Here is what I know and what comes to my mind right now:

> 1. anything but INSTEAD rules are unsafe

How so?  I agree that volatile functions are problematic, but unless
there's one of those in the picture I think rules work pretty much as
documented.

> 3. the snapshots behaviour of an expanded statement is a bit confusing if it 
> contains multiple statements which causes problems with the rather frequent 
> attempts to build rules with upsert'is behaviour

Again, not sure what you're complaining about here.

> A very trivial, seemingly innocuous, but totally broken usage of rules:

The problem illustrated here is all down to nextval() being volatile,
no?

			regards, tom lane