Hi Charles,

I'm not well informed about this but I can tell you that our main warehouse is running 9.1 and our test warehouse is running 8.3. My colleague, Biren, performed the upgrade to 9.1. As a user I have been unaware of any difference.

I'd assume that since the warehouse is built on the Kohana 2.3 framework and uses the database library to connect to the database there is every liklihood of 8.4 remaining supported since changing the framework would be a large task.

Jim Bacon

Hi Charles
Its not quite so simple as that, because the report library contains custom queries which bypass the database libraries of kohana and we also use custom views on the db for reusable queries which  can use pg specific functions. In fact recently we've found some use for a function called array_agg which requires pg 8.4 +, though it is only in an optional report and the optional individuals and associations module, so the core requirement for 8.3 has not yet changed. If you are going straight to 8.4 then this shouldn't be a problem anyway.
John

Updating from 8.4 or 8.3 to 9.1 is not straight forward. As you need to take back up for everything, uninstall the old version and reinstall the new version. Also you do need to reinstall the postgis as well. because 9.3 automatically support the postgis 1.5.

if you don't write lots of queries than worth keeping 8.4 or 8.3 as 9.1 provides relatively sophesticated query tool.