I finally went through the compilation of postgres. My last problem was solved by using flex instead of lex. However I had another problem when I tried to run initdb. It seems that the library libpq.sl is looked for relative to the directory where the command is launched from. for example the first time I tried to run initdb I had a message like /usr/lib/dld.sl: Can't open shared library: ../../interfaces/libpq/libpq.sl /usr/lib/dld.sl: No such file or directory IOT trap (core dumped) I solved this problem by running initdb for example from the directory /usr/src/pgsql/src/test/regress. In this case the library libpq.sl was looked for in /usr/src/pgsql/src/interfaces/libpq so that worked out. How can I change the path of this library ? The path for libpq.sl should be /usr/local/pgsql/lib and it seems that this library is looked for in ../../interfaces/libpq ??? Franck Sgard LASH/DGCB URA CNRS 1652 ENTPE, Rue Maurice Audin 69518 Vaulx-en-Velin Cedex France tel: 0472047740 FAX: 0472047241