pgsql: Improve performance of binary_upgrade_set_pg_class_oids(). - Mailing list pgsql-committers

From Nathan Bossart
Subject pgsql: Improve performance of binary_upgrade_set_pg_class_oids().
Date
Msg-id E1sP5ZY-000C00-Ml@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Improve performance of binary_upgrade_set_pg_class_oids().

This function generates the commands that preserve the OIDs and
relfilenodes of relations during pg_upgrade.  It is called once per
relevant relation, and each such call executes a relatively
expensive query to retrieve information for a single pg_class_oid.
This can cause pg_dump to take significantly longer when
--binary-upgrade is specified, especially when there are many
tables.

This commit improves the performance of this function by gathering
all the required pg_class information with a single query at the
beginning of pg_dump.  This information is stored in a sorted array
that binary_upgrade_set_pg_class_oids() can bsearch() for what it
needs.  This follows a similar approach as commit d5e8930f50, which
introduced a sorted array for role information.

With this patch, 'pg_dump --binary-upgrade' will use more memory,
but that isn't expected to be too egregious.  Per the mailing list
discussion, folks feel that this is worth the trade-off.

Reviewed-by: Corey Huinker, Michael Paquier, Daniel Gustafsson
Discussion: https://postgr.es/m/20240418041712.GA3441570%40nathanxps13

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/2329cad1b93f268c0ec6848732c6db43eb46156c

Modified Files
--------------
src/bin/pg_dump/pg_dump.c        | 140 ++++++++++++++++++++++++++-------------
src/tools/pgindent/typedefs.list |   1 +
2 files changed, 95 insertions(+), 46 deletions(-)


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