I am currently with a group that fields PHP applications on top of Oracle 11g databases. We currently use OCI8 in a RHEL6/Apache environment for our homegrown PHP apps and sites. We are looking at using Drupal 7 to help stream-line our development process as well as make our web apps a bit more visually appealing. (engineers not artists here!).
The problem we have run into is that it seems Drupal 7 does not see or recognize the OCI8 driver as valid for its install. It apparently wants us to use PDO_OCI which we have no experience with.
Does anyone out there run a Drupal 7/Oracle 11g combo that could share their experiences and which driver they use? My googling of the subject has led me to believe the PDO driver may be inferior in some respects to OCI8 for BLOB handling. This is a concern as we do a lot of user upload file sharing as BLOBs stored in the database rather than as files on the OS.
Drupal needs PDO and won't work with native drivers like OCI8. Contact Andrea Gariboldi, the maintainer of the Oracle adapter for Drupal http://drupal.org/project/oracle. He maintains a number of customer sites running Drupal. He will be able to help you make a decision.
The main PDO_OCI issues with LOBs are: (1) no CLOB support due to original creator being unsure how to handle CLOBs in a portable way across all databases (2) a crash doing multi-row fetches of BLOBs (potential patch in https://bugs.php.net/bug.php?id=57702)
There are other issues with PDO_OCI including no connection pooling and no statement caching. It's a pity the community interest in PDO_OCI hasn't been greater and so no one is maintaining it. Even the core PDO layer isn't getting much attention - there was idle talk recently about moving PHP away from PDO.