Peter Geoghegan <> writes:
> On Mon, Apr 21, 2014 at 5:28 PM, Tom Lane <> wrote:
>> We used to have one.  It was a big bottleneck --- and this was years
>> ago, when the buffer manager was much less scalable than it is today.
>> (IIRC, getting rid of a central lock was one of the main advantages
>> of the current clock sweep code over its predecessor.)

> Yes, it was. This is a major advantage of clock sweep, and anything
> that replaces it will need to maintain the same advantage. Didn't
> someone indicate that clock sweep could beat ARC around that time,
> presumably for this reason? If no one did, then my reading of a
> variety of other papers on caching indicates that this is probably the
> case.

ARC *was* the predecessor algorithm.  See commit 5d5087363.

                        regards, tom lane

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