"David Monarchi" <david(dot)e(dot)monarchi(at)gmail(dot)com> writes:
> CREATE INDEX domain_alexa_stock_ticker_dom ON domain_dom
> USING btree (alexa_contactinfo___companystockticker___symbol_dom)
> WHERE NOT alexa_contactinfo___companystockticker___symbol_dom IS NULL;
Try spelling that as "foo is not null", instead. There's a limit to the
complexity of the planner's predicate-proving ability ...
regards, tom lane