Updates and Patches
I've said several times throughout this book that data warehousing DBAs need to ride the bleeding edge of Oracle releases and patches. But, often the temptation exists to do things the OLTP way and wait six months before installing a new release or patch. I cannot stress how wrong this is. A successful data warehouse is going to depend heavily on key Oracle features. Queries need a star transformation explain plan, which needs hash joins, bitmap indexes, and statistics; data loads need parallel, direct mode inserts; and aggregates need either parallel, direct mode inserts or parallel, enabled “upserts” (i.e., the new MERGE command).
It's exactly these new features that have the most bugs, especially for large volumes of data ...
Get Oracle® DBA Guide to Data Warehousing and Star Schemas now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
