Michael Glaesemann <grzm@xxxxxxxxxxxxxxx> writes: > On Jun 27, 2007, at 18:18 , Keary Suska wrote: >> Is it possible to have a user-defined function (a plpqsql function) >> as the >> argument to a default clause that issues SELECTs on other tables? > Not according to the documentation: > http://www.postgresql.org/docs/8.2/interactive/sql-createtable.html What those docs say is that you can't have a naked sub-SELECT in the DEFAULT expression. This is to some extent an implementation limitation --- we don't do planning on DEFAULT expressions. You can definitely get around it by hiding the sub-SELECT in a function. Whether that is a good idea is another question entirely ... it seems a bit questionable, but on the other hand time-varying defaults like "default now()" have time-honored usefulness, so I'm not quite sure why I feel uncomfortable with it. regards, tom lane
