How to fix Extension does not exist in PostgreSQL

Connect to PostgreSQL and query the available extensions:

SELECT * FROM pg_available_extensions WHERE name = 'pg_trgm';

If this returns no results, the extension is not available and you need to install the supporting files.

On most Linux systems, extensions come in a separate package. Install it:

Ubuntu/Debian:

sudo apt-get install postgresql-contrib

CentOS/RHEL:

sudo yum install postgresql-contrib

Fedora:

sudo dnf install postgresql-contrib

After installation, restart PostgreSQL or reconnect to see the extensions.

Once the extension files are installed, create the extension in your database. Connect as a superuser (usually postgres):

psql -U postgres -d your_database

Then create the extension:

CREATE EXTENSION IF NOT EXISTS pg_trgm;

Use IF NOT EXISTS to avoid errors if the extension is already installed. Check that it was created:

\dx

If using AWS RDS, Google Cloud SQL, Azure Database, or similar:

1. Check if the extension is in the allowed list for your service
2. Some providers require enabling extensions via parameter groups or settings
3. Not all extensions are supported by managed services
4. If your required extension is unsupported, you may need to use a self-hosted PostgreSQL instance or choose an alternative extension

For example, AWS RDS allows you to create extensions directly if they are supported, but some extensions require additional setup or are not available at all.

After creating the extension, verify it is available:

\dx

This lists all installed extensions. You should see your extension (e.g., pg_trgm) listed.

You can now use the extension's functions and data types:

CREATE INDEX idx_gin_text ON my_table USING gin(column_name gin_trgm_ops);