> > > * Order duplicate index entries by tid
> > In other words - add tid to index key: very old idea.
> I was thinking during index creation, it would be nice to
> order them by tid, but not do lots of work to keep it that way.
I hear this "not do lots of work" so often from you -:)
Days of simplicity are gone, Bruce. To continue, this project
requires more and more complex solutions.
> > > * Add queue of backends waiting for spinlock
> > We shouldn't mix two different approaches for different
> > kinds of short-time internal locks - in one cases we need in
> > light lmgr (when we're going to keep lock long enough, eg for IO)
> > and in another cases we'd better to proceed with POSIX' mutex-es
> > or semaphores instead of spinlocks. Queueing backends waiting
> > for spinlock sounds like nonsense - how are you going to protect
> > such queue? With spinlocks? -:)
> Yes, I guess so but hopefully we can spin waiting for the queue lock
> rather than sleep. We could use POSIX spinlocks/semaphores now but we
> don't because of performance, right?
No. As long as no one proved with test that mutexes are bad for
Funny, such test would require ~ 1 day of work.
> Should we be spinning waiting for spinlock on multi-cpu machines? Is
> that the answer?
What do you mean?
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|Next:||From: Bruce Momjian||Date: 2001-07-30 17:58:15|
|Subject: Re: Performance TODO items|
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|Subject: Re: SIGCHLD handler in Postgres C function. |