Horton

Re: delta relations in AFTER triggers

Kevin Grittner <kgrittn@gmail.com>

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From: Kevin Grittner <kgrittn@gmail.com>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, David Fetter <david@fetter.org>, Kevin Grittner <kgrittn@ymail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Heikki Linnakangas <hlinnakangas@vmware.com>, Amit Khandekar <amit.khandekar@enterprisedb.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2016-11-02T14:57:01Z
Lists: pgsql-hackers

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On Sun, Oct 30, 2016 at 10:35 AM, Kevin Grittner <kgrittn@gmail.com> wrote:

> SPI support would also
> allow us to consider using set logic for validating foreign keys,
> instead of the one-row-at-a-time approach currently used.

Just as a proof of concept for this I used the attached test case
to create foreign keys using current techniques versus set-oriented
queries with the transition-tsr code.  These probably can be
improved, since this is a "first cut" off the top of my head.

The delete of about one million rows from a "parent" table with no
matching rows in the "child" table, and no index on referencing
column in the child table, took 24:17.969 using current triggers
and 00:03.262 using the set-based triggers.  Yes, that reduces
current run time for that case by 99.78%

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Don't permit transition tables with TRUNCATE triggers.

  2. Pass EXEC_FLAG_REWIND when initializing a tuplestore scan.

  3. Faster expression evaluation and targetlist projection.

  4. Remove obsoleted code relating to targetlist SRF evaluation.

  5. Implement syntax for transition tables in AFTER triggers.