Bitmasks

[Ivan Voras <ivoras@xxxxxx>]

Can indexes be used for bit-filtering queries? For example:

create table tt (
  flags integer not null default 0,
  str   varchar
);

select * from tt where (flags & 16) != 0;

I suspected radix trees could be used for this but it seems it doesn't 
work that way.

If not, is there a way of quickly filtering by such "elements of a set" 
that doesn't involve creating 32 boolean fields (which would also need 
to be pretty uselessly indexed separately)?

Would strings and regular expressions work?