Work with pgsql

I have followed the various instructions for installing, enabling, and setting up the Views Alpha Pager, but cannot get it to work on any of my views. I made sure to add sort criteria of node title or author.

Here is the error message I get:
warning: pg_query() [function.pg-query]: Query failed: ERROR: function left(text, integer) does not exist HINT: No function matches the given name and argument types. You may need to add explicit type casts. in mysite/includes/database.pgsql.inc on line 125.

Any hope for using this module? I have a long glossary that needs to be paginated by alphabet.