Hi there, I successfully renamed one of the columns of the primary key of one of my tables (it is used in one of the foreign keys, too -- I think, this is the problem). Unfortunately, the constraint (rule system?) wasn't updated by "alter table" -- have a look: ---------------------------------------------------------------------- db=# create table blatt_schaeden ( nummer smallint not null, datum date not null, typ smallint not null, klasse smallint, schaden smallint, primary key (nummer,datum,typ), foreign key (nummer) references blatt, foreign key (typ) references blatt_schadenstyp ); CREATE db=# alter table blatt_schaeden rename column nummer to blatt_nummer; ALTER db=# update blatt_schaeden set klasse = 0 where schaden=0; ERROR: constraint <unnamed>: table blatt_schaeden does not have an attribute nummer ---------------------------------------------------------------------- Do you consider this as a bug? There are similar items in the TODO file, related to "alter table add" ... Thanks for your attention, Ulf postgreSQL 7.0.2, i386 Linux 2.2.15/Redhat-6.something -- ====================================================================== Ulf Mehlig <[EMAIL PROTECTED]> Center for Tropical Marine Ecology/ZMT, Bremen, Germany ----------------------------------------------------------------------