# What is AshPostgres?

AshPostgres is the PostgreSQL `Ash.DataLayer` for [Ash Framework](https://hexdocs.pm/ash). This is the most fully-featured Ash data layer, and unless you need a specific characteristic or feature of another data layer, you should use `AshPostgres`.

> ### What versions are supported? {: .info}
>
> Any version higher than 13 is fully supported. Versions lower than this can be made to work, but certain edge cases may need to be manually handled. This becomes more and more true the further back in versions that you go.

Use this to persist records in a PostgreSQL table or view. For example, the resource below would be persisted in a table called `tweets`:

```elixir
defmodule MyApp.Tweet do
  use Ash.Resource,
    data_layer: AshPostgres.DataLayer

  attributes do
    integer_primary_key :id
    attribute :text, :string
  end

  relationships do
    belongs_to :author, MyApp.User
  end

  postgres do
    table "tweets"
    repo MyApp.Repo
  end
end
```

The table might look like this:

| id  | text            | author_id |
| --- | --------------- | --------- |
| 1   | "Hello, world!" | 1         |

Creating records would add to the table, destroying records would remove from the table, and updating records would update the table.