Chris Browne <cbbrowne@acm.org> writes:
> If the field is immaterial in terms of the size of the table, then it
> won't help materially.
> If you were going to index on it, however, THAT would make it
> significant for indices involving the "genre" column. Fitting more
> tuples into each page is a big help, and this would help.
For a multicolumn index it might help to replace int4 by int2. For a
single-column index, alignment constraints on the index entries will
prevent you from saving anything :-(
regards, tom lane