LockAcquire has a "dontWait" parameter, which do just what I want.
The executor level calls "heap_open(relid, RowShareLock)" when doing "FOR UPDATE"s. Should we define something like RowShareLockNoWait, so heap_open() or other lower level functions can call LockAcquire() with dontWait set? By the way, is this kind of question on-topic for pgsql-hackers? TIA, -- Paulo Scardine ----- Original Message ----- From: "Bruce Momjian" <[EMAIL PROTECTED]> To: "Tom Lane" <[EMAIL PROTECTED]> Cc: "Paulo Scardine" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Wednesday, July 23, 2003 4:30 PM Subject: Re: [HACKERS] SELECT FOR UPDATE NOWAIT > Tom Lane wrote: > > "Paulo Scardine" <[EMAIL PROTECTED]> writes: > > > - Where is the best place to put this? > > > > I think it would be a really *bad* idea to put it in LockAcquire; that > > risks breaking things that you don't want broken. > > > > Whether it's special syntax or a GUC variable, the restriction should > > only apply to SELECT FOR UPDATE row locks, perhaps user-commanded LOCK > > TABLE operations, and maybe one or two other places that are known to > > be used only for user-written operations and not for system-initiated > > ones. Those places would need to check whether to do a conditional > > or unconditional lock. > > My original idea was to have it apply only for exclusive locks. It > seemed those were mostly the locks didn't want to wait for. Shared > locking pg_class is something that you would want to wait for. > > -- > Bruce Momjian | http://candle.pha.pa.us > [EMAIL PROTECTED] | (610) 359-1001 > + If your life is a hard drive, | 13 Roberts Road > + Christ can be your backup. | Newtown Square, Pennsylvania 19073 > > ---------------------------(end of broadcast)--------------------------- > TIP 7: don't forget to increase your free space map settings > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.490 / Virus Database: 289 - Release Date: 16/6/2003 ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
