The following bug has been logged on the website:
Bug reference: 7661
Logged by: Stuart Bishop
Email address: stuart@stuartbishop.net
PostgreSQL version: 9.1.6
Operating system: Ubuntu 12.04
Description: =
The pgstattuple upgrade from unpackaged script expects the pgstatindex
function to exist, but it does not on particularly old databases (My
pgstattuple originally installed with 8.3 or 8.4?).
# create extension pgstattuple;
ERROR: function "pgstattuple" already exists with same argument types
# create extension if not exists pgstattuple from unpackaged;
ERROR: function pgstatindex(text) does not exist