Horton

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

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: John Naylor <john.naylor@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2019-02-20T12:55:58Z
Lists: pgsql-hackers

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On Mon, Feb 11, 2019 at 10:48 PM John Naylor
<john.naylor@2ndquadrant.com> wrote:
>
> On 2/9/19, Amit Kapila <amit.kapila16@gmail.com> wrote:
> > On Tue, Feb 5, 2019 at 3:25 PM John Naylor <john.naylor@2ndquadrant.com>
> > wrote:
> >>
> >> On Tue, Feb 5, 2019 at 4:04 AM Amit Kapila <amit.kapila16@gmail.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

Commits

  1. Improve code comments in b0eaa4c51b.

  2. During pg_upgrade, conditionally skip transfer of FSMs.

  3. Add more tests for FSM.

  4. Doc: Update the documentation for FSM behavior for small tables.

  5. Make FSM test portable.

  6. Avoid creation of the free space map for small heap relations, take 2.

  7. Move page initialization from RelationAddExtraBlocks() to use, take 2.

  8. Avoid creation of the free space map for small heap relations.

  9. In bootstrap mode, don't allow the creation of files if they don't already