pgsql: Split ExecUpdate and ExecDelete into reusable pieces

Started by Alvaro Herreraover 4 years ago4 messagescomitters
Jump to latest
#1Alvaro Herrera
alvherre@2ndquadrant.com

Split ExecUpdate and ExecDelete into reusable pieces

Create subroutines ExecUpdatePrologue / ExecUpdateAct /
ExecUpdateEpilogue, and similar for ExecDelete.

Introduce a new struct to be used internally in nodeModifyTable.c,
dubbed ModifyTableContext, which contains all context information needed
to perform these operations, as well as ExecInsert and others.

This allows using a different schedule and a different way of evaluating
the results of these operations, which can be exploited by a later
commit introducing support for MERGE. It also makes ExecUpdate and
ExecDelete proper shorter and (hopefully) simpler.

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Japin Li <japinli@hotmail.com>
Reviewed-by: Zhihong Yu <zyu@yugabyte.com>
Discussion: /messages/by-id/202202271724.4z7xv3cf46kv@alvherre.pgsql

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/25e777cf8e547d7423d2e1e9da71f98b9414d59e

Modified Files
--------------
src/backend/executor/nodeModifyTable.c | 781 ++++++++++++++++++++-------------
src/tools/pgindent/typedefs.list | 2 +
2 files changed, 484 insertions(+), 299 deletions(-)

#2Amit Langote
Langote_Amit_f8@lab.ntt.co.jp
In reply to: Alvaro Herrera (#1)
Re: pgsql: Split ExecUpdate and ExecDelete into reusable pieces

Hi Alvaro,

On Thu, Mar 17, 2022 at 7:47 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

Split ExecUpdate and ExecDelete into reusable pieces

Create subroutines ExecUpdatePrologue / ExecUpdateAct /
ExecUpdateEpilogue, and similar for ExecDelete.

Introduce a new struct to be used internally in nodeModifyTable.c,
dubbed ModifyTableContext, which contains all context information needed
to perform these operations, as well as ExecInsert and others.

This allows using a different schedule and a different way of evaluating
the results of these operations, which can be exploited by a later
commit introducing support for MERGE. It also makes ExecUpdate and
ExecDelete proper shorter and (hopefully) simpler.

I noticed that we failed to update a comment mentioning a now obsolete
parameter of ExecCrossPartitionUpdate(). Attached a patch to fix that
and an old typo in the same sentence.

--
Amit Langote
EDB: http://www.enterprisedb.com

Attachments:

fix-obsolete-comment.patchapplication/octet-stream; name=fix-obsolete-comment.patchDownload+4-3
#3Amit Langote
Langote_Amit_f8@lab.ntt.co.jp
In reply to: Amit Langote (#2)
Re: pgsql: Split ExecUpdate and ExecDelete into reusable pieces

On Sat, Mar 19, 2022 at 12:59 PM Amit Langote <amitlangote09@gmail.com> wrote:

On Thu, Mar 17, 2022 at 7:47 PM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:

Split ExecUpdate and ExecDelete into reusable pieces

Create subroutines ExecUpdatePrologue / ExecUpdateAct /
ExecUpdateEpilogue, and similar for ExecDelete.

Introduce a new struct to be used internally in nodeModifyTable.c,
dubbed ModifyTableContext, which contains all context information needed
to perform these operations, as well as ExecInsert and others.

This allows using a different schedule and a different way of evaluating
the results of these operations, which can be exploited by a later
commit introducing support for MERGE. It also makes ExecUpdate and
ExecDelete proper shorter and (hopefully) simpler.

I noticed that we failed to update a comment mentioning a now obsolete
parameter of ExecCrossPartitionUpdate(). Attached a patch to fix that
and an old typo in the same sentence.

Actually, I also noticed that the v16 patch you posted in the "Re: a
misbehavior of partition row movement (?)" thread contained this same
fix. I like the wording in that patch, though I guess it's better to
commit the fix separately from the big patch there, which I guess may
have been your intention anyway. So, here's a v2.

--
Amit Langote
EDB: http://www.enterprisedb.com

Attachments:

fix-obsolete-comment_v2.patchapplication/octet-stream; name=fix-obsolete-comment_v2.patchDownload+3-3
#4Alvaro Herrera
alvherre@2ndquadrant.com
In reply to: Amit Langote (#3)
Re: pgsql: Split ExecUpdate and ExecDelete into reusable pieces

On 2022-Mar-19, Amit Langote wrote:

Actually, I also noticed that the v16 patch you posted in the "Re: a
misbehavior of partition row movement (?)" thread contained this same
fix. I like the wording in that patch, though I guess it's better to
commit the fix separately from the big patch there, which I guess may
have been your intention anyway. So, here's a v2.

Yeah, I was of two minds about pushing it separately -- and you
mentioning it now pushed me to do that. So, it's done now.

--
Álvaro Herrera Valdivia, Chile — https://www.EnterpriseDB.com/
"Hay que recordar que la existencia en el cosmos, y particularmente la
elaboración de civilizaciones dentro de él no son, por desgracia,
nada idílicas" (Ijon Tichy)