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

On Mon, Apr 9, 2012 at 11:32 AM, Noah Misch <noah(at)leadboat(dot)com> wrote:
> On Mon, Apr 09, 2012 at 03:35:06PM +0200, Andres Freund wrote:
>> On Monday, April 09, 2012 03:25:36 PM Robert Haas wrote:
>> > contrib/xml2 isn't doing us much harm beyond being an ugly wart, but non-
>> > SELECT rules are a land mine for the unwary at best.
>> Which we could start deprecating now btw. since INSTEAD triggers landed in
>> 9.1. There were quite some use-cases for non-select rules that couldn't be
>> fullfilled before but I think saying that we won't support those rules for
>> more than 3 releases or so might be a good idea. I have seen too many bugs
>> being caused by experienced people not realizing the pitfalls of rules.
>
> A new documentation section "Pitfalls of the Rule System" discussing the known
> hazards would help users immediately and be far easier to adopt.  In contrast
> to the breathless vitriol against rules that periodically appears on these
> lists, current documentation barely hints at the trouble.

We already have a section on rules-vs-triggers, but it presents them
as being about equal in terms of advantages and disadvantages; in
fact, there are some implications that rules are generally superior.
This is a minority point of view on this list, and a rewrite of that
section seems overdue.

--
Robert Haas
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