Horton

Re: support for MERGE

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Cc: Simon Riggs <simon.riggs@enterprisedb.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Zhihong Yu <zyu@yugabyte.com>, Daniel Westermann <dwe@dbi-services.com>, Amit Langote <amitlangote09@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, Japin Li <japinli@hotmail.com>, Erik Rijkers <er@xs4all.nl>, Jaime Casanova <jcasanov@systemguards.com.ec>
Date: 2022-03-09T17:38:03Z
Lists: pgsql-hackers

Attachments

I attach MERGE v14.  This includes a fix from Amit Langote for the
problem I described previously, with EvalPlanQual not working correctly.
(I had failed to short-circuit the cross-partition update correctly.)
Now the test case is enabled again, and it passes with the correct
output.

0001 is as before; the only change is that I've added a commit message.
Since this just moves some code around, I intend to get it pushed very
soon.

0002 is the ExecUpdate/ExecDelete split.  I cleaned up the struct
definitions a bit more, but it's pretty much as in the previous version.

0003 is the actual MERGE implementation.  Many previous review comments
have been handled, and several other things are cleaner than before.
I haven't made any changes for work_mem handling in ModifyTable's
transition tables, though, and haven't attempted to address concurrent
INSERT.

-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/

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.