pg_regresql

Overview

Activate it with LOAD pg_regresql or session_preload_libraries.

Version

Build

You can build the RPM / DEB packages for pg_regresql using pig build:

pig build pkg pg_regresql         # build RPM / DEB packages

Install

You can install pg_regresql directly. First, make sure the PGDG and PIGSTY repositories are added and enabled:

pig repo add pgsql -u          # Add repo and update cache

Install the extension using pig or apt/yum/dnf:

• Install
• pig
• dnf
• apt

pig install pg_regresql;          # Install for current active PG version

pig ext install -y pg_regresql -v 18  # PG 18
pig ext install -y pg_regresql -v 17  # PG 17
pig ext install -y pg_regresql -v 16  # PG 16
pig ext install -y pg_regresql -v 15  # PG 15
pig ext install -y pg_regresql -v 14  # PG 14

dnf install -y pg_regresql_18       # PG 18
dnf install -y pg_regresql_17       # PG 17
dnf install -y pg_regresql_16       # PG 16
dnf install -y pg_regresql_15       # PG 15
dnf install -y pg_regresql_14       # PG 14

apt install -y postgresql-18-pg-regresql   # PG 18
apt install -y postgresql-17-pg-regresql   # PG 17
apt install -y postgresql-16-pg-regresql   # PG 16
apt install -y postgresql-15-pg-regresql   # PG 15
apt install -y postgresql-14-pg-regresql   # PG 14

Preload:

shared_preload_libraries = 'pg_regresql';

Create Extension:

CREATE EXTENSION pg_regresql;

Usage

Syntax:

regresql init postgres://localhost/mydb
regresql add src/sql/
regresql update
regresql test

Sources: README, Product page

RegreSQL is documented upstream as a language-agnostic SQL regression testing tool for PostgreSQL, not as a CREATE EXTENSION-style in-database module. It discovers .sql files, runs them against PostgreSQL, snapshots expected output, and tracks query plan changes.

Quick Start

The README’s basic workflow is:

regresql init postgres://localhost/mydb
regresql discover
regresql add src/sql/
regresql update
regresql test

This initializes a test suite, discovers query files, creates plan definitions, captures expected output, and runs regression checks.

What It Tracks

The upstream docs emphasize:

• expected query output snapshots
• EXPLAIN plan baselines
• sequential scan warnings
• migration-related query regressions
• CI-oriented output formats such as junit, json, pgtap, and github-actions

Query Files and Plans

RegreSQL works with normal SQL files and supports multiple queries per file using -- name: annotations:

-- name: get-user-by-id
SELECT * FROM users WHERE id = :id;

Plan files provide test parameters:

"1":
  id: 42
"2":
  id: 100

Snapshots and Migrations

The tool can build and restore database snapshots and compare query behavior across migrations:

regresql snapshot build
regresql snapshot restore
regresql migrate --script db/migrations/001_add_column.sql

Installation

The README documents installation via Homebrew or Go:

brew tap boringsql/boringsql
brew install regresql

or

go install github.com/boringsql/regresql@latest

PostgreSQL client tools such as pg_dump, pg_restore, and psql are required for snapshot commands.