Re: Hard problem with concurrency

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