BUG #16012: vacuum full, something weird

On Wed, Sep 18, 2019 at 9:25 AM PG Bug reporting form <
noreply@postgresql.org> wrote:

The following bug has been logged on the website:

Bug reference: 16012
Logged by: Richard Klaumann
Email address: richard.klaumann@gmail.com
PostgreSQL version: 9.5.3
Operating system: Centos 7.x
Description:

Hello,
First sorry for my english.
Today we store our byteas in tables. We are moving these files to
storages.
During the process we set the bytea column to null and execute vacum full
(in the table itself and in the table pg_catalog.pg_largeobject).

pg_largeobject has nothing to do with data stored in bytea columns.

In some tables we continue with pg_total_relation_size> 24GB (practically
the initial size). Data in the toast table.
If I run a new vacuum full on the main table, the space is freed.

Data can only be freed once every snapshot that could possibly be
interested in it has closed.

So if you have any long-running statements, or long-open transactions with
isolation level above read-committed, it would inhibit the removal of the
data by vacuum full (or any other level of vacuum)

Cheers,

Jeff