# FAQ

Common errors and fixes for PostgreSQL backup operations.

Most PostgreSQL backup failures fall into three categories: insufficient privileges on the backup user, connection or resource errors during the dump, and version mismatches when restoring. The entries below cover the most common cases.

## Backup failing due to insufficient privileges

If your backup fails with a permission denied error, your backup user likely lacks the privileges required for `pg_dump` to read all objects in the database. Grant the necessary access:

```sql
GRANT CONNECT ON DATABASE "your_database_name" TO backup_user;
GRANT SELECT ON ALL TABLES IN SCHEMA your_schema_name TO backup_user;
GRANT SELECT ON ALL SEQUENCES IN SCHEMA your_schema_name TO backup_user;
```

Replace `your_database_name`, `your_schema_name`, and `backup_user` with your actual values. Re-run the backup after applying the grants.

## SSL SYSCALL error: EOF detected

You may see one or more of the following errors during a backup:

- `pg_dump: error: Error message from server: SSL SYSCALL error: EOF detected`
- `pg_dump: error: Dumping the contents of table "my_table" failed: PQgetCopyData() failed`
- `pg_dump: detail: Error message from server: could not receive data from server: Connection timed out`

These errors typically occur when the database server has very limited RAM or CPU available during the dump. The connection is dropped mid-transfer because the server cannot sustain the query. To resolve it, check your database server's resource usage at the time of the backup and consider scheduling the backup during off-peak hours or upgrading the server plan.

## pg_restore: unsupported file header version error

The error `pg_restore: error: unsupported version (1.xx) in file header` occurs when your local `pg_restore` binary is older than the PostgreSQL version that created the dump. You need to upgrade `pg_restore` to match or exceed the server version.

**On macOS (Homebrew):**

```bash
brew update
brew install libpq
# or if already installed
brew upgrade libpq
```

Then add `libpq` to your PATH in `~/.zshrc` or `~/.bash_profile`:

```bash
export PATH="/opt/homebrew/opt/libpq/bin:$PATH"
```

Reload your terminal and verify:

```bash
pg_restore --version
```

**On Ubuntu:**

```bash
sudo apt update
sudo apt install -y libpq-dev
```

**Info:**
If you see `pg_restore: error: input file appears to be a text format dump. Please use psql`, your backup is in plain text (`.sql`) format, not custom format. Use `psql` to restore it instead of `pg_restore`. See [Restore a PostgreSQL backup](https://simplebackups.com/docs/database-backup/postgresql-backup/restore-a-postgresql-backup) for both restore paths.