some useless files may be left behind ?

Hi All,

We have a cluster on windows 2008 server "PostgreSQL 9.1.15, compiled by Visual C++ build 1500, 64-bit"
After trying to create new databases concurrently npgsql endpoint reached default commandtimeout (20 seconds).

This results in following log entries on the server:
2015-04-30 08:47:14 CEST WARNING: could not remove file or directory "base/64111031": Directory not empty
2015-04-30 08:47:14 CEST WARNING: some useless files may be left behind in old database directory "base/64111031"
2015-04-30 08:47:14 CEST ERROR: canceling statement due to user request
2015-04-30 08:47:14 CEST STATEMENT: CREATE DATABASE database WITH ENCODING='UTF8' OWNER=owner TEMPLATE=custom_template

The directory is empty now.
Question is, will auto vacuum clean this up eventually?
Should I be concerned ?

Any thoughts or comments are appreciated. Thanks!

Bo Thorbjørn Jensen