Resources that use AshPostgres.DataLayer use a Repo to access the database.

This repo is a thin wrapper around an Ecto.Repo.

You can use Ecto.Repo's init/2 to configure your repo like normal, but instead of returning {:ok, config}, use super(config) to pass the configuration to the AshPostgres.Repo implementation.

Installed Extensions

To configure your list of installed extensions, define installed_extensions/0

Extensions can be a string, representing a standard postgres extension, or a module that implements AshPostgres.CustomExtension. That custom extension will be called to generate migrations that serve a specific purpose.

Extensions that are relevant to ash_postgres:

• "ash-functions" - This isn't really an extension, but it expresses that certain functions should be added when generating migrations, to support the || and && operators in expressions.
• "uuid-ossp" - Sets UUID primary keys defaults in the migration generator
• "pg_trgm" - Makes the AshPostgres.Functions.TrigramSimilarity function available
• "citext" - Allows case insensitive fields to be used
• "vector" - Makes the AshPostgres.Functions.VectorCosineDistance function available. See AshPostgres.Extensions.Vector for more setup instructions.

def installed_extensions() do
  ["pg_trgm", "uuid-ossp", "vector", YourCustomExtension]
end

Transaction Hooks

You can define on_transaction_begin/1, which will be invoked whenever a transaction is started for Ash.

This will be invoked with a map containing a type key and metadata.

%{type: :create, %{resource: YourApp.YourResource, action: :action}}

Additional Repo Configuration

Because an AshPostgres.Repo is also an Ecto.Repo, it has all of the same callbacks.

In the Ecto.Repo.init/2 callback, you can configure the following additional items:

• :tenant_migrations_path - The path where your tenant migrations are stored (only relevant for a multitenant implementation)
• :snapshots_path - The path where the resource snapshots for the migration generator are stored.