Re: Good name for new lock type for VACUUM?

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Peter Eisentraut <peter_e(at)gmx(dot)net>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Good name for new lock type for VACUUM?
Date: 2001-06-22 20:58:01
Message-ID: 200106222058.f5MKw1v23156@candle.pha.pa.us
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> Tom Lane writes:
>
> > Awhile ago I said that I wanted to create a new flavor of table-level
> > lock for concurrent VACUUM to get on a table.
>
> > I'm having a hard time coming up with a name, though. I originally
> > called it "VacuumLock" but naming it after its primary use seems bogus.
>
> Not that a name like "share row exclusive" is any less bogus. ;-)
>
> I've been staring at the lock names for an hour now and the best name I've
> come up with is SHARE UPDATE EXCLUSIVE, as in "share update, otherwise
> exclusive" (the implication being that update would allow select as well),
> or some permutation thereof.
>
> Any other constructs that follow the existing patterns lead to
> significantly less desirable names like
>
> EXCLUSIVE ROW EXCLUSIVE == like ROW EXCLUSIVE, but self-exclusive, or
>
> ROW EXCLUSIVE SHARE == like SHARE, but allows ROW EXCLUSIVE

Sounds good. I documented the lock types as best I could in the LOCK
manual page. I think that is as good as we can do to explain them.

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Bruce Momjian | http://candle.pha.pa.us
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