I've tried to up the pg gem on a pretty average Rails app to 0.15.0 and once done, I get messages such as this one whenever a rake task is executed:
NOTICE: identifier "/var/www/staging.wemakeit.ch/site/vendor/bundle/ruby/1.9.1/bin/rake" will be truncated to "/var/www/staging.wemakeit.ch/site/vendor/bundle/ruby/1.9.1/bin/"
Most likely, this is not an issue of the pg gem, I guess notices have been suppressed on previous versions of it.
However, I don't have a clue as of where to look for the source of this problem. The message means that a statement contains "/var/www/staging.wemakeit.ch/site/vendor/bundle/ruby/1.9.1/bin/rake" which is interpreted as an attribute (column). And since attributes can be only 64 chars max, it will be truncated.
Issue #156 resolved