The following bug has been logged on the website:
Bug reference: 11991
Logged by: Tomasz Kimaczynski
Email address: tomek(at)rai(dot)pl
PostgreSQL version: 9.2.9
Operating system: Windows 2003,2008,2012 & FreeBSD
Description:
Recently, I realized pg_dump dangerous activity. In case when no dump is
made because of any error, created file size is 0 bytes. In case when this
file is used in simple backup procedure which make copy of dump file - 0
bytes files overwrite earlier correct dump files.
And we have no copies.
Conclusion: pg_dump can not create 0 bytes files - it should create
nothing.
I think it's important.