pgpool_regclass

replacement for regclass

pgpool : replacement for regclass

Overview

ID	Extension	Package	Version	Category	License	Language
5920	pgpool_regclass	pgpool	`4.7.2`	ADMIN	PostgreSQL	C

Attribute	Has Binary	Has Library	Need Load	Has DDL	Relocatable	Trusted
----d--	No	No	No	Yes	no	no

Relationships
See Also	pgbouncer_fdw pgdd meta pg_readme ddlx pg_catcheck
Siblings	pgpool_adm pgpool_recovery

Packages

Type	Repo	Version	PG Major Compatibility	Package Pattern	Dependencies
EXT	PGDG	`4.7.2`	18 17 16 15 14	`pgpool`	-
RPM	PGDG	`4.7.2`	18 17 16 15 14	`pgpool-II-pg$v-extensions`	-
DEB	PGDG	`4.7.2`	18 17 16 15 14	`postgresql-$v-pgpool2`	-

Linux / PG	PG18	PG17	PG16	PG15	PG14
el8.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el8.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el9.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el9.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el10.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
el10.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d12.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d12.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d13.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
d13.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u22.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u22.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u24.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u24.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u26.x86_64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2
u26.aarch64	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2	PGDG 4.7.2

Source

Repository

pgpool.net/

Install

Make sure PGDG repo available:

pig repo add pgdg -u    # add pgdg repo and update cache

Install this extension with pig:

pig install pgpool;		# install via package name, for the active PG version
pig install pgpool_regclass;		# install by extension name, for the current active PG version

pig install pgpool_regclass -v 18;   # install for PG 18
pig install pgpool_regclass -v 17;   # install for PG 17
pig install pgpool_regclass -v 16;   # install for PG 16
pig install pgpool_regclass -v 15;   # install for PG 15
pig install pgpool_regclass -v 14;   # install for PG 14

Create this extension with:

CREATE EXTENSION pgpool_regclass;

Usage

pgpool_regclass: replacement for regclass

The pgpool_regclass extension provides a replacement regclass function used internally by Pgpool-II to handle relation name resolution across multiple backends.

Function

-- Resolve a relation name to its OID, similar to PostgreSQL's regclass cast
SELECT pgpool_regclass('my_table');
SELECT pgpool_regclass('my_schema.my_table');

Purpose

In standard PostgreSQL, casting a string to regclass (e.g., 'my_table'::regclass) resolves the relation name to an OID. However, Pgpool-II needs to determine whether a SQL statement references a temporary table or a regular table to route queries correctly.

The pgpool_regclass function provides this resolution capability as a regular function call rather than a type cast, allowing Pgpool-II to:

Determine if a referenced table exists on the backend
Distinguish temporary tables from permanent tables for proper query routing
Handle schema-qualified table names correctly across pooled connections

Notes

This extension is primarily used internally by Pgpool-II and is not typically called directly by applications
It should be installed on all PostgreSQL backend nodes managed by Pgpool-II
For Pgpool-II 3.0+, this function helps with the check_temp_table feature