Wednesday, June 18, 2008

Re: [GENERAL] Clustering with minimal locking

On Wed, Jun 18, 2008 at 9:26 AM, Decibel! <decibel@decibel.org> wrote:
On Jun 17, 2008, at 11:37 AM, Scott Ribe wrote:
BOOM! Deadlock.

No more likely than with the current cluster command. Acquiring the lock is
the same risk; but it is held for much less time.


Actually, no (at least in 8.2). CLUSTER grabs an exclusive lock before it does any work meaning that it can't deadlock by itself. Of course you could always do something like

BEGIN;
SELECT * FROM a;
CLUSTER .. ON a;
COMMIT;

Which does introduce the risk of a deadlock

Really!!? Am I missing something? How can a single transaction, running synchronous commands, deadlock itself!

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