Horton

Re: support for MERGE

Laurenz Albe <laurenz.albe@cybertec.at>

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From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Justin Pryzby <pryzby@telsasoft.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Amit Langote <amitlangote09@gmail.com>, Japin Li <japinli@hotmail.com>, Zhihong Yu <zyu@yugabyte.com>, Simon Riggs <simon.riggs@enterprisedb.com>, pgsql-hackers@lists.postgresql.org, Tomas Vondra <tomas.vondra@enterprisedb.com>, Daniel Westermann <dwe@dbi-services.com>, Erik Rijkers <er@xs4all.nl>, Jaime Casanova <jcasanov@systemguards.com.ec>, Andres Freund <andres@anarazel.de>
Date: 2022-05-12T06:57:45Z
Lists: pgsql-hackers 
On Wed, 2022-05-11 at 11:33 -0500, Justin Pryzby wrote:
> Also, EXPLAIN output currently looks like this:
> 
> > Merge on ex_mtarget t (actual rows=0 loops=1)
> >   Tuples Inserted: 0
> >   Tuples Updated: 50
> >   Tuples Deleted: 0
> >   Tuples Skipped: 0
> 
> Should the "zero" rows be elided from the text output ?
> And/or, should it use a more compact output format ?
> 
> There are two output formats already in use, so the options would look like
> this:
> 
>    Tuples: Inserted: 1  Updated: 2  Deleted: 3  Skipped: 4
> or
>    Tuples: inserted=1 updated=2 deleted=3 skipped=4
> 
> Note double spaces and capitals.
> That's separate from the question about eliding zeros.

+1 on one of the latter versions, I don't care which one.

Yours,
Laurenz Albe

Commits

  1. Doc fixes for MERGE statement

  2. MERGE docs adjustments

  3. Link to MVCC docs in MERGE docs

  4. Fix EXPLAIN MERGE output when no tuples are processed

  5. Make EXPLAIN MERGE output format more compact

  6. Add support for MERGE SQL command

  7. Split ExecUpdate and ExecDelete into reusable pieces

  8. Add API of sorts for transition table handling in trigger.c

  9. Represent Lists as expansible arrays, not chains of cons-cells.