Re: Double sorting split patch - Mailing list pgsql-hackers

On 04.10.2011 15:10, Alexander Korotkov wrote:

On Tue, Oct 4, 2011 at 1:46 PM, Heikki Linnakangas<
heikki.linnakangas@enterprisedb.com>  wrote:

Ok. Could you phrase that as a code comment?

Here's a version of the patch I've been working on. There's no functional
changes, just a lot of moving things around, comment changes, etc. to
hopefully make it more readable.

Thanks for your work on this patch. Patch with comment is attached.

Thanks, I incorporated that, and did a lot of other comment changes. I included the example you gave earlier on how the first phase of the algorithm works, in a comment. Please review, and if you have some test cases at hand, run them. I think this is ready for commit now.

One more thing:

       /* Allocate vectors for results */
       nbytes = (maxoff + 2) * sizeof(OffsetNumber);
       v->spl_left = (OffsetNumber *) palloc(nbytes);
       v->spl_right = (OffsetNumber *) palloc(nbytes);

Why "maxoff + 2" ? Allocating a few extra bytes is obviously harmless, but I wonder if it was just a leftover from something.