Re: Hard problem with concurrency - Mailing list pgsql-hackers

From Vincent van Leeuwen
Subject Re: Hard problem with concurrency
Date
Msg-id 20030218232718.GN29874@md2.mediadesign.nl
Whole thread Raw
In response to Re: Hard problem with concurrency  (Peter Eisentraut <peter_e@gmx.net>)
Responses Re: Hard problem with concurrency
List pgsql-hackers
On 2003-02-18 20:02:29 +0100, Peter Eisentraut wrote:
> Christopher Kings-Lynne writes:
> 
> > REPLACE INTO anyone? ;)
> 
> The upcoming SQL 200x standard includes a MERGE command that appears to
> fulfill that purpose.
> 

MySQL features a poor-mans aproach to this problem, their REPLACE command:

http://www.mysql.com/doc/en/REPLACE.html
REPLACE works exactly like INSERT, except that if an old record in the table
has the same value as a new record on a UNIQUE index or PRIMARY KEY, the old
record is deleted before the new record is inserted.

I'd love to see this kind of functionality in PG, I've got a database that
caches data which only gets conditional INSERT/UPDATEs, so that would save a
lot of wasted SQL commands.


Vincent van Leeuwen
Media Design



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