[GRASSLIST:3312] Import with r.in.gdal

[Anja Drews]

Dear list,

I am trying to import raster data with r.in.gdal in GRASS 5.0.3.
I get the following error message:

r.in.gdal: error while loading shared libraries: libpq.so.2: cannot open 
shared object file: No such file or directory

In the directory /usr/local/grass5/lib I find the packages libpq.so.1 
and libpq.so.1.2.

What package do I need to install to get libpq.so.2 ?

Thanks for your help,

Anja