“Can somebody please explain to

"Can somebody please explain to me how Oracle Express Analyser / Objects / Server fits into the 9i picture ? Has 9i Release 2 totally replaced it?" asks Jonathon Hill on OTN's OLAP Forum. This is a common question i'm being asked by Express Objects and Analyzer customers, who are wondering when they can think about migrating their existing Express applications to Oracle 9i, and have heard about the existing Express tools not working with 9i OLAP.

Partly, but not entirely, is probably the best answer to Jonathon's question.

As he points out, 9i release 2 has now got the Express multidimensional engine within the database kernel and Oracle refer to 9i now as a 'relational-multidimensional database server'. The multidimensional functionality (referred to as Oracle 9i OLAP) is a pay-extra option for the 9i database and (last time I looked) it cost around 50% of the equivalent Express Server license. It is programmed using the same Express Server 4GL and uses the same data structures, although multidimensional data is now held within Oracle schemas, rather than in Express .db files.

Express databases can therefore be easily copied across to the equivalent 9i OLAP databases, and most program code will run without major modifications. However, Oracle have not ported SNAPI and XCA to Oracle 9i; these protocols are replaced by a new Java OLAP API, together with a new feature where you can use SQL to directly query the multidimensional data. This means that Express applications such as Analyzer, Objects and Administrator, together with OFA and OSA, will not work against Oracle 9i OLAP.

The plan is, that Express applications that use Analyzer or Objects will be replaced with Java applications written using JDeveloper and BI Beans. OFA and OSA will in due course be replaced by Enterprise Planning and Budgeting which uses the new communication protocols; details of this are due soon and Oracle are the best source of info on this. The one exception to this is applications written using Express Web Agent and Web Publisher - these two tools have been ported to 9i OLAP as they don't use SNAPI or XCA, and we've found that they work fine.

So, in summary:

- 9i OLAP within the 9i Database is already a worthy replacement for Express Server. It works more or less the same as Express Server and it's got many advantages over stand-alone Express Server.
- Any applications that use SNAPI (Objects, Analyzer etc) will need to be rewritten using JDeveloper, BI Beans and so on
- Organisations that use OFA and OSA should hold fire until EPB comes out later this year, which will also include tools for migrating OFA and OSA systems.

Express will of course be supported for many years to come (I think until about 2006/7, not sure precisely) and customers are still designing and building solutions using Express Server, Objects and Analyzer.

You can read more about potential Express migration scenarios in this Plus Consultancy whitepaper.