Simon Riggs wrote:
On Sun, 2005-12-18 at 17:07 +1300, Mark Kirkwood wrote:

Tom Lane wrote:


2. transform joins into subselects, then return subselect rows via an
index bitmap. Joins are performed via a bitmap addition process.

Looks like 8.1 pretty much does this right now:


Good analysis.

8.1 doesn't do:
- the transforms sufficiently well (you just performed them manually)

Absolutely - I was intending to note that very point, but it got lost somewhere between brain and fingers :-)

- doesn't AND together multiple bitmaps to assist with N-way joins


Ah yes - I had overlooked that, good point!

Cheers

Mark



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