---
page_title: 'Backend Type: pg'
description: Terraform can store state remotely in a Postgres database with locking.
---

# pg

Stores the state in a [Postgres database](https://www.postgresql.org) version 10 or newer.

This backend supports [state locking](/language/state/locking).

## Example Configuration

```hcl
terraform {
  backend "pg" {
    conn_str = "postgres://user:pass@db.example.com/terraform_backend"
  }
}
```

Before initializing the backend with `terraform init`, the database must already exist:

```
createdb terraform_backend
```

This `createdb` command is found in [Postgres client applications](https://www.postgresql.org/docs/10/reference-client.html) which are installed along with the database server.

We recommend using a
[partial configuration](/language/settings/backends/configuration#partial-configuration)
for the `conn_str` variable, because it typically contains access credentials that should not be committed to source control:

```hcl
terraform {
  backend "pg" {}
}
```

Then, set the credentials when initializing the configuration:

```
terraform init -backend-config="conn_str=postgres://user:pass@db.example.com/terraform_backend"
```

To use a Postgres server running on the same machine as Terraform, configure localhost with SSL disabled:

```
terraform init -backend-config="conn_str=postgres://localhost/terraform_backend?sslmode=disable"
```

## Data Source Configuration

To make use of the pg remote state in another configuration, use the [`terraform_remote_state` data source](/language/state/remote-state-data).

```hcl
data "terraform_remote_state" "network" {
  backend = "pg"
  config = {
    conn_str = "postgres://localhost/terraform_backend"
  }
}
```

## Configuration Variables

The following configuration options or environment variables are supported:

- `conn_str` - (Required) Postgres connection string; a `postgres://` URL
- `schema_name` - Name of the automatically-managed Postgres schema, default `terraform_remote_state`.
- `skip_schema_creation` - If set to `true`, the Postgres schema must already exist. Terraform won't try to create the schema, this is useful when it has already been created by a database administrator.
- `skip_table_creation` - If set to `true`, the Postgres table must already exist. Terraform won't try to create the table, this is useful when it has already been created by a database administrator.
- `skip_index_creation` - If set to `true`, the Postgres index must already exist. Terraform won't try to create the index, this is useful when it has already been created by a database administrator.

## Technical Design

This backend creates one table **states** in the automatically-managed Postgres schema configured by the `schema_name` variable.

The table is keyed by the [workspace](/language/state/workspaces) name. If workspaces are not in use, the name `default` is used.

Locking is supported using [Postgres advisory locks](https://www.postgresql.org/docs/9.5/explicit-locking.html#ADVISORY-LOCKS). [`force-unlock`](/cli/commands/force-unlock) is not supported, because these database-native locks will automatically unlock when the session is aborted or the connection fails. To see outstanding locks in a Postgres server, use the [`pg_locks` system view](https://www.postgresql.org/docs/9.5/view-pg-locks.html).

The **states** table contains:

- a serial integer `id`, used as the key for advisory locks
- the workspace `name` key as _text_ with a unique index
- the Terraform state `data` as _text_