hstore_plruby

Overview

Extension control default_version is 1.0; shipped in the PL/Ruby 2.5.0 package.

Version

Build

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

pig build pkg plruby         # build RPM / DEB packages

Install

You can install plruby 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 plruby;          # Install for current active PG version

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

dnf install -y plruby_18       # PG 18
dnf install -y plruby_17       # PG 17
dnf install -y plruby_16       # PG 16
dnf install -y plruby_15       # PG 15
dnf install -y plruby_14       # PG 14

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

Create Extension:

CREATE EXTENSION hstore_plruby CASCADE;  -- requires: hstore, plruby

Usage

Sources:

• PL/Ruby v2.5.0 README
• hstore_plruby v1.0 control file
• hstore_plruby v1.0 extension SQL

hstore_plruby installs a PostgreSQL transform between hstore and Ruby Hash values for the plruby language. Keys become Ruby strings and values become strings or nil; a compatible Ruby hash can be returned directly as hstore.

Install and Use the Transform

CREATE EXTENSION hstore;
CREATE EXTENSION plruby;
CREATE EXTENSION hstore_plruby;

CREATE FUNCTION ruby_add_hstore_key(hstore)
RETURNS hstore
LANGUAGE plruby
TRANSFORM FOR TYPE hstore
AS $$
  value = args[0]
  value['processed'] = 'yes'
  value
$$;

SELECT ruby_add_hstore_key('id=>42'::hstore);

The transform is used only by functions that declare TRANSFORM FOR TYPE hstore.

Objects and Caveats

• hstore_to_plruby(internal) implements SQL-to-Ruby conversion.
• plruby_to_hstore(internal) implements Ruby-to-SQL conversion.
• The extension version is 1.0, it requires both hstore and plruby, and it is relocatable.
• hstore is a flat string-to-string-or-NULL map. It does not preserve nested Ruby hashes, arrays, or typed numeric values; use jsonb_plruby when those shapes matter.
• PL/Ruby remains untrusted. Installing this transform does not sandbox Ruby code or reduce the privileges required to create PL/Ruby functions.