Re: TABLESAMPLE patch - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: TABLESAMPLE patch
Date
Msg-id 551BEC16.2080204@2ndquadrant.com
Whole thread Raw
In response to Re: TABLESAMPLE patch  (Petr Jelinek <petr@2ndquadrant.com>)
Responses Re: TABLESAMPLE patch
List pgsql-hackers
On 03/15/15 16:21, Petr Jelinek wrote:
>
> I also did all the other adjustments we talked about up-thread and
> rebased against current master (there was conflict with 31eae6028).
>

Hi,

I did a review of the version submitted on 03/15 today, and only found a 
few minor issues:

1) The documentation of the pg_tablesample_method catalog is missing   documentation of the 'tsmpagemode' column, which
wasadded later.
 

2) transformTableEntry() in parse_clause modifies the comment, in a way   that made sense before part of the code was
movedto a separate   function. I suggest to revert the comment changes, and instead add   the comment to
transformTableSampleEntry()

3) The "shared" parts of the block sampler in sampling.c (e.g. in   BlockSampler_Next) reference Vitter's algorithm
(boththe code and   comments) which is a bit awkward as the only part that uses it is   analyze.c. The other samplers
usingthis code (system / bernoulli)   don't use Vitter's algorithm.
 
   I don't think it's possible to separate this piece of code, though.   It simply has to be in there somewhere, so I'd
recommendadding here   a simple comment explaining that it's needed because of analyze.c.
 

Otherwise I think the patch is OK. I'll wait for Petr to fix these 
issues, and then mark it as ready for committer.

What do you think, Amit? (BTW you should probably add yourself as 
reviewer in the CF app, as you've provided a lot of feedback here.)

--
Tomas Vondra                   http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services



pgsql-hackers by date:

Previous
From: Robert Haas
Date:
Subject: Re: Parallel Seq Scan
Next
From: Amit Kapila
Date:
Subject: Re: TABLESAMPLE patch