Tom Kyte On Data Warehousing vs OLTP, and Oracle 9i New DW Features

There's a couple of good questions just appeared on asktom.com:

The first concerns the differences between data warehouses and OLTP systems, particularly with regard to developer and DBA skills;

"How is a data warehousing database different from a regular database? I usually find that data warehousing is seen as a separate skill. Why ? What are the areas (in a nutshell ) wherein a data warehouse database differes from a regular database?"

In addition, another poster asks about the new data warehousing features in Oracle 9i:

"Could you help me in answering the question below (asked by my team mate in relation to upgrade to 9i for data warehousing application):

There are lots of "new features" which is just Oracle bundling their old products eg OLAP server is just Express I think,
dw builder is old, data mining is just the algorithms, not visualisation, but not too much extra except for some more performance tuning capability around views (bitmap join index), lead&lag function upgrades and extra partitioning capability which were first introduced in 8i."