8.0.X and the ARC patent

FYI, core has discussed the pending IBM ARC patent and the usage of
those ideas in 8.0.

Tom has found a 2Q cache algorithm that predates the ARC patent and is
very similar to ARC. The major difference is that it doesn't auto-size
the ARC sub-buffers.

Core believes it is best to backpatch this 2Q algorithm into 8.0.X to
avoid any possible patent problems if the patent is granted and
enforced.

We are testing the use of the 2Q code to see if it has any performance
impact. The 8.0.X release that uses 2Q will have more extensive testing
than a normal minor release. 8.1 will have a new cache algorithm that
hopefully will remove the buffer contention problems experienced by SMP
machines.

For development, this means we will _not_ have a shortened, non-initdb
8.1 release but a regular release cycle with the typical big batch of
features.

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