On Thu, Sep 22, 2011 at 1:49 PM, Robert Haas <robertmh...@gmail.com> wrote: > My thought was that it would avoid the need to do any character > incrementing at all. You could just start scanning forward as if the > operator were >= and then stop when you hit the first string that > doesn't have the same initial substring.
But the whole problem is that not all the strings with the initial substring are in a contiguous block. The best we can hope for is that they're fairly dense within a block without too many non-matching strings. The example with / shows how that can happen. If you're looking for foo/% and you start with foo/ you'll find: foo/ foo0 foo/0 foo1 foo/1 ... Even just case-insensitive collations don't put all the strings with a common prefix in a contiguous block. If you're searching for foo% you'll find: foo Foobar foobar -- greg -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
