Error "cannot delete file, will retry" in log

Question

There is an error in my log, I see it again and again:

I i.q.c.ColumnPurgeOperator cannot delete file, will retry [path=C:\QuestDB\bin\qdb\db\lolTableNOWAL\default\lolColumn.d.1438, errno=5]

And client says:

00000: Timeout expired on waiting for the async command execution result [instance=20]

After awhile the DB crashes.

What is happening?

Answer 1

Found answer in the docs.

If you are using Windows, we recommend disabling Windows Defender. Windows Defender will scan each new file that it sees. If a file is being scanned, it cannot be deleted. Therefore, QuestDB creates files, Windows Defender scans them, QuestDB goes to clean up and cannot delete the files being scanned.

After disabling Defender, it works.