From: Zeugswetter Andreas $Date: 2002/11/11 20:04:05 $ On AIX 4.3.2 PostgreSQL compiled with the native IBM compiler xlc (vac.C 5.0.1) passes all regression tests. Other versions of OS and compiler should also work. If you don't have a powerpc or use gcc you might see rounding differences in the geometry regression test. Use the following configure flags in addition to your own if you have readline or libz there: --with-includes=/usr/local/include --with-libraries=/usr/local/lib There will probably be warnings about 0.0/0.0 division and duplicate symbols which you can safely ignore. Compiling PostgreSQL with gcc (2.95.3) on AIX also works. You need libm.a that is in the fileset bos.adt.libm. (Try the following command.) $ lslpp -l bos.adt.libm Since the mktime() function does not work on AIX for dates before 1970, all localtime formatted datetimes will not use daylight-saving time for dates before 1970.