Forum OpenACS Development: Legacy OpenACS under Oracle 12c

Posted by Michael Aram on
Dear community,

one of our customers who is currently running an OpenACS 5.4 under Oracle 10g plans an upgrade of the database server to Oracle 12c. (The DB Server is managed by their IT department.)

However, as they are more or less reluctant to pay for a "real" application layer (OpenACS) upgrade as well, they want to give the "export dump - import dump" approach a try.

I would expect that either this will not work at all or that it will seemingly work, but the application is then "stuck" in the sense that future upgrades are hardly possible because the upgrade scripts were written for an older OpenACS version.

I have to admit that I have no OACS-Oracle experience at all, so this assumption comes from my lessons learned from PostgreSQL upgrades.

Any comments are welcome!

PS: The compatibility matrix does not mention 12c at all, and there is a "maybe" for 11g, but I am optimistic because of

Posted by Andrew Piskorski on
At work, we recently upgraded from Oracle 10g to 12c, while (so far) still using a very old version of OpenACS. It's working fine. We did a physical Oracle upgrade using RMAN backups, not export/import, although I expect export would work ok. Oracle has been quite backwards compatible, so any OpenACS upgrade scripts written for 8i will probably still run fine on 12c, but I haven't tried that. We had one (questionably written) query that worked on 10g but failed on 12c (a fairly easy fix), and a few ugly queries that got incredibly slow, presumably from some change between the 10g and 12c query planners. No showstoppers.

So I think your customer's plan will probably work fine, as long as they have the right programmers available to fix the occasional bug.

Wait, or do you mean they want to try to run the latest OpenACS 5.9.1 code, while simply importing the data from their old OpenACS 5.4 system? No, of COURSE that (probably) won't work. If it DID, why would anyone go to all the trouble of writing those upgrade scripts? Keep running the same old OpenACS 5.4 code and everything should be ok. If you want to use that data in a new OpenACS 5.9.1 system, well that's what the upgrade scripts are for.

Posted by Brian Fenton on
Hi Michael!

yes, we have recently moved from 11g to 12c as part of a bigger project to move our installations from AOLserver to Naviserver, and from Linux to Windows.

The 12c part was definitely the smoothest part of the project. The only issues we came across were minor:

1. WM_CONCAT function has been removed in 12c - lots of solutions online
2. the 'sync' option to rebuild an index has been removed in 12c - try replacing with EXEC CTX_DLL.SYNC_INDEX( 'cr_rev_content_index' );
3. some internal Oracle views are slower in 12c e.g. USER_CONS_COLUMNS - make sure any joins are also joined by the OWNER column

Happy to help if you have any other queries/concerns.


Posted by Michael Aram on
Thank you both very much for your helpful responses!