# Postgres error: 'could not access status of transaction' when PostgREST runs LISTEN

## The error

You'll see this in your database logs:

- **Error:** `could not access status of transaction`
- **Detail:** `Could not open file "pg_xact/[ID]": No such file or directory`
- **Application:** PostgREST (shown as `PostgREST 13.0.5` or similar)
- **Command:** `LISTEN`

If you see the first error message without the pg\_xact detail, or outside PostgREST, it may be a different issue.

## What's happening

This is an upstream Postgres [bug](http://postgresql.org/message-id/flat/VE1PR03MB531295B1BDCFE422441B15FD92499%40VE1PR03MB5312.eurprd03.prod.outlook.com) but affects PostgREST. The notification queue gets stuck and tries to access old transaction IDs that no longer exist.

## Fix

Run this command in the [SQL editor](https://supabase.com/dashboard/project/_/sql/new):

```sql
select pg_notification_queue_usage();
```

This clears the stuck queue. Your Data API will become responsive again, and the errors should stop.

## If it happens again

Run the command above again.

If you upgrade to PostgREST v14.8+, the logs will include a `HINT` that tells you to run `SELECT pg_notification_queue_usage();`. You can upgrade PostgREST and Postgres in [Infrastructure Settings](https://supabase.com/dashboard/project/_/settings/infrastructure).