Re: PostgreSQL 9.0 - Mailing list pgsql-general

From Jeff Davis
Subject Re: PostgreSQL 9.0
Date
Msg-id 1170182549.22436.15.camel@dogma.v10.wvs
Whole thread Raw
In response to Re: PostgreSQL 9.0  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: PostgreSQL 9.0  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
On Tue, 2007-01-30 at 02:35 -0800, Joshua D. Drake wrote:
> > Something different than rules?
> > (http://www.postgresql.org/docs/8.2/interactive/rules.html) (They exist for a
> > while, I've just linked the latest released docs...)
> >
> Quite. Rules are not updateable views. Rules are a hacked up way to
> create an updateable view.

I wouldn't go that far. Rules can do things that updatable views can't
do. Sometimes a view can't be updatable because an update to that view
would be ambiguous (as far as the system knows), but you can still use
the well-defined rules system to *tell* the system what you want an
update to mean.

Updatable views provide a subset of the functionality of rules, but they
do it automatically without much effort on the part of the DBA. That's
great, but it won't replace rules.

Regards,
    Jeff Davis


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