Horton

Re: tableam vs. TOAST

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Prabhat Sahu <prabhat.sahu@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-09-06T14:59:54Z
Lists: pgsql-hackers

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On Thu, Sep 5, 2019 at 4:07 PM Andres Freund <andres@anarazel.de> wrote:
> Yea, makes sense to me.

OK, done.  Here's the remaining patches again, with a slight update to
the renaming patch (now 0002).  In the last version, I renamed
toast_insert_or_update to heap_toast_insert_or_update but did not
rename toast_delete to heap_toast_delete.  Actually, I'm not seeing
any particular reason not to go ahead and push the renaming patch at
this point also.  I guess there's a question as to whether I should
more aggressively add "heap" to the names of the other functions in
heaptoast.h, but I'm kinda "meh" about that.  It seems likely that
other AMs will need their own versions of toast_insert_or_update() and
toast_delete(), but they shouldn't really need their own version of,
say, toast_flatten_tuple_to_datum(), and the point there is that we're
building a DatumTuple, so calling it
heap_toast_flatten_tuple_to_datum() seems almost misleading.  I'm
inclined to leave all that stuff alone for now.

0001 needs more thought, as discussed.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. tableam: New callback relation_fetch_toast_slice.

  2. tableam: Allow choice of toast AM.

  3. Move heap-specific detoasting logic into a separate function.

  4. Code cleanup for toast_fetch_datum and toast_fetch_datum_slice.

  5. Rename some toasting functions based on whether they are heap-specific.

  6. Create an API for inserting and deleting rows in TOAST tables.

  7. Split tuptoaster.c into three separate files.

  8. tableam: Move heap-specific logic from needs_toast_table below tableam.