On 14 Jul 2003 at 5:18, Mike Mascari wrote:
> I agree. However a common scenario that has appeared on these lists is
> a request for an atomic 'CREATE IF NOT EXISTS, ELSE REPLACE' without
> race conditions. Because Oracle doesn't rollback the transaction, it
> is implementable in SQL. For PostgreSQL, you either need to use
> various locking techniques which reduces concurrency or be prepared to
> resubmit the entire transaction. Savepoints and/or nested transactions
> may alleviate the situation in the future, however.
Recognising the need of such, SQL standard has been extended to accommodate a
merge command which is create if not exists else update types.
Correct me if I am wrong..
BTW, what's wrong with select for update in such scenario?
Bye
Shridhar
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