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