Horton

Re: COPY FROM WHEN condition

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>, Surafel Temesgen <surafel3000@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Adam Berlin <berlin.ab@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-01-29T21:12:40Z
Lists: pgsql-hackers 
Hi,

On 2019-01-30 10:05:35 +1300, David Rowley wrote:
> On Wed, 30 Jan 2019 at 04:22, Andres Freund <andres@anarazel.de> wrote:
> > I think I might have a patch addressing the problem incidentally. For pluggable storage I slotified copy.c, which also removes the first heap_form_tuple. Quite possible that nothing more is needed. I've removed the batch context altogether in yesterday's rebase, there was no need anymore.
> 
> In your patch, where do the batched tuples get stored before the heap
> insert is done?

There's one slot for each batched tuple (they are reused). Before
materialization the tuples solely exist in tts_isnull/values into which
NextCopyFrom() directly parses the values.  Tuples never get extracted
from the slot in copy.c itself anymore, table_multi_insert() accepts
slots.  Not quite sure whether I've answered your question?

Greetings,

Andres Freund

Commits

  1. Remove unused struct member, enforce multi_insert callback presence.

  2. Separate per-batch and per-tuple memory contexts in COPY

  3. Fix handling of volatile expressions in COPY FROM ... WHERE

  4. Allow COPY FROM to filter data using WHERE conditions

  5. Remove obsolete netbsd dynloader code