OLAP Oracle continues to be outpaced by Microsoft in the OLAP space. Although Oracle is stronger in the relational OLAP space, Microsofts multidimensional OLAP server is sophisticated, has broad third-party industry support and is included at no extra charge in its database. Its even very easy to use the OLAP Server included with Microsofts SQL Server to do analysis on data located in Oracle databases.In addition, Oracle provides no built-in data gateways to import, export or query data stored in non-Oracle databases, something Microsoft and IBM include as standard in their database servers. Oracle can import just text or XML files on its own; native third-party database gateways are available but sold separately. Oracle9i Release 2 includes several features that are attractive but not so compelling that they would incite upgrade plans. For example, Oracle9i Release 2 provides features that improve data warehousing, including the DataGuard Logical Standby Database option, which lets organizations use a standby database to process database queries. Using this option, the standby database is run in normal mode and is updated using normal SQL commands, so administrators are also able to add indexes or materialized views and use the database for reporting or for data analysis queries. Previously, the standby database had to be run in recovery mode, which does not allow user queries. Another data warehousing win is support for data compression. Data compression of repeated values in columns allows more data to fit on a disk block and so improves speed for queries that need to access a large set of rows. Compressed blocks also allow more data to fit into Oracles buffer cache, thus lowering memory demands. The combination of block compression, bit map indexes (another unique Oracle feature) and materialized views (which are supported by DB2 and Microsofts SQL Server) makes Oracle a great platform for in-place, relational OLAP or data warehousing jobs. Oracle9i Release 2 also provides more help in setting database parameters for optimal performance and makes it easier to access Oracles data recovery tools through a new SQL extension called Flashback Query. While Oracle9is Log Miner continues to be the more general-purpose tool for reading and undoing past changes from the log, the Flashback Querys powerful "as of" extension to the SQL select command let us undo mistakes or look at older versions of data from a normal SQL query tool. eWeek Labs West Coast Technical Director Timothy Dyck can be reached at firstname.lastname@example.org.
Both Oracles OLAP and data mining components use APIs that are new (as in Oracle9i Release 1, which shipped last summer) and so far poorly supported by other data query and analysis tool vendors.