Currently, src/interfaces/libpq/win32.mak builds a statically-linked
library "libpq.lib", a debug dll "libpq.dll", import library for the
debug dll "libpqdll.lib", a release dll "libpq.dll", import library for
the release dll "libpqdll.lib".  To avoid naming clashes, I would make
the debug dll and import libraries "libpqd.dll" and "libpqddll.lib".

Basically, the debug build uses the cl flags: "/MDd /D _DEBUG", and the
release build uses the cl flags "/MD /D NDEBUG".  Usually the debug
build has a "D" suffix on the file name, so for example:

libpqd.dll     libpq, debug build
libpqd.lib     libpq, debug build, import library
libpq.dll      libpq, release build
libpq.lib      libpq, release build, import library

David Turner