Re: MERGE ... RETURNING

jian he <jian.universality@gmail.com>

From: jian he <jian.universality@gmail.com>

To: Dean Rasheed <dean.a.rasheed@gmail.com>

Cc: walther@technowledgy.de, Jeff Davis <pgsql@j-davis.com>, Vik Fearing <vik@postgresfriends.org>, Gurjeet Singh <gurjeet@singh.im>, Isaac Morland <isaac.morland@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2024-03-13T06:44:12Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add RETURNING support to MERGE.
- c649fa24a42b 17.0 landed
doc: Improve a couple of places in the MERGE docs.
- 97d4262683ac 17.0 landed
- d4c573d8e81e 16.3 landed
- a875743ff402 15.7 landed
doc: improve description of privileges for MERGE and update glossary.
- 4bc8f29088f8 17.0 landed
- 3b6728910ace 16.2 landed
- ff772853d02e 15.6 landed
Fix RLS policy usage in MERGE.
- c2e08b04c9e7 17.0 cited
Fix leak of LLVM "fatal-on-oom" section counter.
- 4f4d73466d71 17.0 cited
Implement outer-level aggregates to conform to the SQL spec, with
- e649796f128b 7.4.1 cited

Hi, some minor issues:

<synopsis>
[ WITH <replaceable class="parameter">with_query</replaceable> [, ...] ]
MERGE INTO [ ONLY ] <replaceable
class="parameter">target_table_name</replaceable> [ * ] [ [ AS ]
<replaceable class="parameter">target_alias</replaceable> ]
USING <replaceable class="parameter">data_source</replaceable> ON
<replaceable class="parameter">join_condition</replaceable>
<replaceable class="parameter">when_clause</replaceable> [...]
[ RETURNING * | <replaceable
class="parameter">output_expression</replaceable> [ [ AS ]
<replaceable class="parameter">output_name</replaceable> ] [, ...] ]

here the "WITH" part should have "[ RECURSIVE ]" like:
[ WITH [ RECURSIVE ] <replaceable
class="parameter">with_query</replaceable> [, ...] ]

+      An expression to be computed and returned by the <command>MERGE</command>
+      command after each row is merged.  The expression can use any columns of
+      the source or target tables, or the <xref linkend="merge_action"/>
+      function to return additional information about the action executed.
+     </para>
should be:
+      An expression to be computed and returned by the <command>MERGE</command>
+      command after each row is changed.


one minor issue:
add
`
table sq_target;
table sq_source;
`
before `-- RETURNING` in src/test/regress/sql/merge.sql, so we can
easily understand the tests.