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: Justin Pryzby <pryzby@telsasoft.com>
Cc: pgsql-hackers@lists.postgresql.org, 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>, Japin Li <japinli@hotmail.com>, Erik Rijkers <er@xs4all.nl>, Jaime Casanova <jcasanov@systemguards.com.ec>
Date: 2022-02-11T18:21:43Z
Lists: pgsql-hackers 
On 2022-Jan-28, Justin Pryzby wrote:

> Have you looked at code coverage ?  I have an experimental patch to add that to
> cirrus, and ran it with this patch; visible here:
> https://cirrus-ci.com/task/6362512059793408

Ah, thanks, this is useful.  I think it is showing that the new code is
generally well covered, but there are some exceptions, particularly
ExecMergeMatched in some concurrent cases (TM_Deleted and
TM_SelfModified after table_tuple_lock -- those code pages have
user-facing errors but are not covered by any tests.)


How does this work?  I notice it is reporting for
src/bin/pg_upgrade/relfilenode.c, but that file is not changed by this
patch.

-- 
Álvaro Herrera              Valdivia, Chile  —  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.