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Re: Performance TODO items

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: "Mikheev, Vadim" <vmikheev(at)SECTORBASE(dot)COM>
Cc: PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>
Subject: Re: Performance TODO items
Date: 2001-07-30 17:15:40
Message-ID: 200107301715.f6UHFe310576@candle.pha.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
> > New TODO entries are:
> > 
> > 	* 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.

> > 	* 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?

Should we be spinning waiting for spinlock on multi-cpu machines?  Is
that the answer?

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

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Next:From: Fernando NasserDate: 2001-07-30 17:24:26
Subject: Re: Revised Patch to allow multiple table locks in "Unison"
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Subject: RE: Performance TODO items

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