Re: gistchoose vs. bloat

On Tue, 2012-09-04 at 19:21 +0400, Alexander Korotkov wrote:

> New version of patch is attached. Parameter "randomization" was
> introduced. It controls whether to randomize choose. Choose algorithm
> was rewritten.
>
Review comments:

1. Comment above while loop in gistRelocateBuildBuffersOnSplit needs to
be updated.

2. Typo in two places: "if randomization id required".

3. In gistRelocateBuildBuffersOnSplit, shouldn't that be:
splitPageInfo = &relocationBuffersInfos[bufferIndex];
not:
splitPageInfo = &relocationBuffersInfos[i];

4. It looks like the randomization is happening while trying to compare
the penalties. I think it may be more readable to separate those two
steps; e.g.

/* create a mapping whether randomization is on or not */
for (i = FirstOffsetNumber; i <= maxoff; i = OffsetNumberNext(i))
offsets[i - FirstOffsetNumber] = i;

if (randomization)
/* randomize offsets array */

for (i = 0; i < maxoff; i++)
{
offset = offsets[i];
...
}

That's just an idea; if you think it's more readable as-is (or if I am
misunderstanding) then let me know.

Regards,
Jeff Davis