Re: Full Text Index Scanning

Matt Warner <matt@warnertechnology.com> writes:
> Doesn't seem to work either. Maybe something changed in 9.1?
> create index test_idx on testtable using gin(to_tsvector(wordcolumn||'
> '||reverse(wordcolumn)));
> ERROR:  functions in index expression must be marked IMMUTABLE

That's not the same case he tested.  The single-parameter form of
to_tsvector isn't immutable, because it depends on the default text
search configuration parameter.  It should work, AFAICS, with the
two-parameter form.

                       regards, tom lane