Re: Re: [HACKERS] Postgresql OO Patch

> Tom Lane wrote:
>
> > It's kinda fuzzy, but in practice I'd say the readers of pgsql-hackers
> > and maybe pgsql-general.
>
> One more time for the <general> mailing list...
>
> Hands up if you have objections to the patch I recently submitted for
> postgresql. It fixes the long standing bit-rot / bug that DELETE and
> UPDATE don't work on inheritance hierarchies, and it adds the ONLY
> syntax as mentioned in SQL3 and as implemented by Informix. The downside
> is it breaks compatibility with the old inheritance syntax. But there is
> a backward compatibility mode. I.e. "SELECT * FROM foobar*" becomes
> "SELECT * FROM foobar", and "SELECT * from foobar" becomes "SELECT *
> FROM ONLY foobar".
>
> Benefits:
> *) SQL3 says it.
> *) Informix does it.
> *) If you never used inheritance it doesn't affect you.
> *) Performance is unaffected.
> *) There is a backwards compatibility mode via SET.
> *) My own experience says strongly that this will greatly reduce
> programmer bugs because the default is much more common (laziness
> usually leads us to discard the "*" to the detriment of future
> inheritance data model changes.)
> *) It is more OO since by default a <subclass> IS A <baseclass>.
>
> Disadvantage:
> *) You need to make a one line change to any programs that use
> inheritance to include the back-compatibility SET mode.

Well, it seems many of us forgot the valid arguments for the change.
Matching SQL3 and Informix's behavior is a good thing. Considering how
broken our current inheritance implementation is, backward compatibility
is not a must, and you have a SET option for that too. Great.

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