After over 1.5 years of development (since 29/11, 2005), plus number of developers contribution, and help of Drupal 6.x schema API, a new Oracle driver for Drupal 6.x is now ready for testing.
The latest version of Oracle driver overcome a lot of Oracle-specific limitation, and able to work well as like as existing Drupal database driver, e.g. MySQL and PgSQL. On the other hand, according to a simple stress test result, Oracle driver is able to keep similar performance as like as other drivers.
Special features include: isolated LOBs value handling (require additional LOBs patch to Drupal 6.x), overcome limitation in table/column/constraint naming with maximum 30 characters, rewrite table/column/constraint name if it is Oracle-specific reserved word, overcome PHP5 OCI8 oci_num_rows() bug on SELECT query, etc. On the other hand, according to number of other Drupal 6.x core patches, most core queries are now Oracle friendly. The above features will also benefit in others database driver implementation.
It is closed to complete, but still not perfect. First of all, as stated above, an additional LOBs patch to Drupal 6.x is required by the latest version of Oracle driver. Since this patch was submitted after code freeze, we will need some more effort about its commit.
Secondly, table prefix is limited in maximum 10 characters, even though size of table name is now unlimited. This is due to a chicken-and-egg problem, and seems no simple solution. BTW, 10 characters are usually enough for table prefix.
More over, SQL statements are required to follow Drupal's query coding standard strictly. This is mainly because Oracle driver will take some regex replacement to incoming SQL statement, for overcome those Oracle-specific limitation.
Finally, your help are required. Our end goal is to have an official support of enterprise-level database within Drupal 6.x. Oracle support is one of our target, but not the only one. We need your help to point out any missing hook for other database driver implementation, e.g. DB2, SQLite, MSSQL, ODBC, etc.
If you are interesting about this topic, please feel free to test it out, and send back your feedback, bugs, and suggestions.
Drupal 6.x LOBs patch issue: http://drupal.org/node/147947
Drupal 6.x Oracle driver issue: http://drupal.org/node/39260
