Re: WIP: Avoid creation of the free space map for small tables

From: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
To: John Naylor <john(dot)naylor(at)2ndquadrant(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: WIP: Avoid creation of the free space map for small tables
Date: 2019-02-20 12:55:58
Message-ID: CAA4eK1JdEwEUgPpmz1PAsrZ0eUFmLBcJ18n_G1enf=MkD=zroA@mail.gmail.com
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On Mon, Feb 11, 2019 at 10:48 PM John Naylor
<john(dot)naylor(at)2ndquadrant(dot)com> wrote:
>
> On 2/9/19, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > On Tue, Feb 5, 2019 at 3:25 PM John Naylor <john(dot)naylor(at)2ndquadrant(dot)com>
> > wrote:
> >>
> >> On Tue, Feb 5, 2019 at 4:04 AM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> >> wrote:
> > This is certainly a good test w.r.t code coverage of new code, but I
> > have few comments:
> > 1. The size of records in test still depends on alignment (MAXALIGN).
> > Though it doesn't seem to be a problematic case, I still suggest we
> > can avoid using records whose size depends on alignment. If you
> > change the schema as CREATE TABLE fsm_check_size (num1 int, num2 int,
> > str text);, then you can avoid alignment related issues for the
> > records being used in test.
>
> Done.
>
> > 2.
> > +-- Fill most of the last block
> > ..
> > +-- Make sure records can go into any block but the last one
> > ..
> > +-- Insert large record and make sure it does not cause the relation to
> > extend
> >
> > The comments in some part of the test seems too focussed towards the
> > algorithm used for in-memory map. I think we can keep these if we
> > want, but it is required to write a more generic comment stating what
> > is the actual motive of additional tests (basically we are testing the
> > functionality of in-memory map (LSM) for the heap, so we should write
> > about it.).
>
> Done.
>

Thanks, the modification looks good. I have slightly changed the
commit message in the attached patch. I will spend some more time
tomorrow morning on this and will commit unless I see any new problem.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Attachment Content-Type Size
v3-0001-Add-more-tests-for-FSM.patch application/octet-stream 6.6 KB

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