Subject: Re: [HACKERS] Efficient DELETE Strategies
From: Hannu Krosing <hannu@tm.ee>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Christoph Haller <ch@rodos.fzk.de>, pgsql-sql@postgresql.org,
	pgsql-hackers@postgresql.org
In-Reply-To: <5619.1023717387@sss.pgh.pa.us>
References: <200206101142.NAA16854@rodos>  <5619.1023717387@sss.pgh.pa.us>
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Date: 10 Jun 2002 19:33:48 +0200
Message-Id: <1023730428.4092.64.camel@taru.tm.ee>
Mime-Version: 1.0

On Mon, 2002-06-10 at 15:56, Tom Lane wrote:
> Christoph Haller <ch@rodos.fzk.de> writes:
> > Based on an entry in the mailing list from 30 Oct 2001 
> > about efficient deletes on subqueries, 
> > I've found two ways to do so (PostgreSQL 7.2.1): 
> > ...
> > Is there a way to put the second form (more complicated, but faster) 
> > in one statement? 
> > Or is there even a third way to delete, which I cannot see? 

...
 
> AFAIK this extension would be utterly trivial to implement, since all
> the machinery is there already --- for 99% of the backend, it doesn't
> matter whether a FROM-item is implicit or explicit.  We'd only need to
> argue out what the syntax should be.  I could imagine
> 
> 	DELETE FROM relation_expr [ , table_ref [ , ... ] ]
> 	[ WHERE bool_expr ]
> 
> or
> 
> 	DELETE FROM relation_expr [ FROM table_ref [ , ... ] ]
> 	[ WHERE bool_expr ]

What about

DELETE relation_expr FROM relation_expr [ , table_ref [ , ... ] ]
 	[ WHERE bool_expr ]

or

DELETE relation_expr.* FROM relation_expr [ , table_ref [ , ... ] ]
 	[ WHERE bool_expr ]


--------------
Hannu