How to create a new database with the hstore extension already installed?

sql

prompt-engineering

best-practices

data-types

byAnton Shumikhin·Nov 21, 2024

CREATE DATABASE newDB WITH TEMPLATE template0;
\c newDB;
CREATE EXTENSION IF NOT EXISTS hstore;

Perform CREATE DATABASE with the pristine template0, connect to your database, and finally CREATE EXTENSION for hstore. You'll have a fresh database with hstore ready from the outset.

Enabling hstore globally: Step by Step

If you want hstore ready in every new database, here's your recipe:

Access your PostgreSQL instance using the psql command.
Enable hstore in the template1 database:

psql -d template1 -c 'CREATE EXTENSION IF NOT EXISTS hstore;' --execute order 'Install hstore'

Executes a command that installs the hstore extension within the template1 database.

When you construct a new database, PostgreSQL uses template1 as the blueprint:

CREATE DATABASE not_hstore_less; -- because hstore is never where you least expect it

Your new database will inherit hstore along with other settings from template1.

Caution: Tempering template1 affects all future databases, wield with discretion.

Verifying your setup and common usage

Once you've armed your new database with the hstore extension, afford some time to verify the installation and acquaint yourself with the basics:

Confirm hstore installation in your database:

psql -d not_hstore_less -c '\dx' -- hstore, show thyself!

The output will include hstore in the list of installed extensions if everything was successful.

Access hstore in queries in your new database like this:

SELECT 'key' => 'value'::hstore; -- secret handshake of hstore users

Tackling multiple databases

While template1 allows for a consistent hstore extension, there may be times when you prefer individually configured databases. Here's how to nail those:

New DB, different template

Need a database sans hstore? Employ a different template while creating it:

CREATE DATABASE ordinary_db WITH TEMPLATE template0; -- plain Jane, no hstore

Drop hstore when not needed

If hstore was an unwelcome guest in one of your databases, show it the door:

\c not_hstore_less;
DROP EXTENSION hstore; -- vote hstore off the island

This sends hstore packing from your chosen database, leaving the rest unaffected.

Demystifying hstore

Hstore's a robust data type allowing key-value pair storage within a single PostgreSQL value. It’s your go-to for semi-structured data or when you need some flexibility to add more details without meddling with the existing schema.

Hstore Benefits:

Adaptability: Conveniently store and retrieve dynamic attributes for your entities.
Indexing: Amplify search performance with GIN or GIST indexes on hstore columns.
Aggregation: Collate multiple row-wise key-value pairs into one hstore column.

Hstore: The Right Choice

When dealing with evolving attributes that frequently mutate.
For early-stage prototyping where rigid schema changes could kill momentum.
Storing user-centric preferences or settings that can be as unique as snowflakes.

Best practices and considerations

When incorporating hstore, reflect on these best practices and considerations:

Mindful schema design

Conservatively introduce hstore to prevent bloating with complex queries and impeding performance.

Protecting your precious data

Before fiddling with templates, back up! Always protect your data before embarking on any modification. Also, remember template changes don't walk on water when migrating across databases; You'll need to backup and restore extensions specifically.

Post-hstore deployment maintenance

Occasional TLC like reindexing and space reallocation may be needed for hstore columns over time, just like any other feature handling constant updates and deletions.