Slow tab completion w/ lots of tables

Greetings,
 When doing tab-completion under 9.1, pg_table_is_visible(oid) is slow and is ending up as the first thing tested
againstall the rows in pg_class.  Increasing the cost of pg_table_is_visible() up to 10 causes it to move to the end of
thetests, which improves things greatly- I thought there was a plan to make that the default..?
 
 This is with 9.1.4.
 After researching this a bit, I'm left wondering why we're using substring() to do the matching test.  I don't see any
easyway to index a substring() call which can be of any size (depending on how many characters are preceding the user
hitting'tab').  On the other hand, using LIKE with 'string%' and indexing with varchar_pattern_ops should give us a
niceindex which could be used for tab completion, right?  If no one points out an obvious flaw in that, I'll take a
lookat making that happen.
 
     Thanks!
    Stephen