SAP supports index key compression since Oracle 10.2. This feature is very useful in some cases, so let's take a closer look how it works and in which cases it can improve your performance or save disk space.
Index compression is implemented at index leaf block level (only available for b-tree indexes). Each unique combination of the compressed column values is stored in an "internal" (=prefix) table and replaced in the index row by a pointer to that prefix table entry.
The benefit of compression depends on the number of unique combinations:
There is a lot of new stuff out there nowadays, regarding products and/or functionality or others. This is also true for Oracle and in short it’s not easy to follow all those innovations and/or new products. So from time to time I have a watch on stuff that interests me on the YouTube Oracle E-Learning
Six topic areas, 30 sessions, several Oak Table speakers, and a keynote from Tom Kyte.
There Is No Such Thing As “Pure OLTP”
There is no such thing as “pure OLTP.” How true! And that’s why you are supposed to buy Exadata for your Oracle OLTP/ERP deployment—at least that’s what I’ve heard.
Part I of this series on the topic of Oracle OLTP/ERP on Exadata Database Machine has brought quite a bit of feedback my way. Most of the feedback came from independent consultants who have built a practice around Exadata. I did, however, hear from an Oracle customer that has chosen to migrate their Oracle Database 10g ERP system from a cluster of old AMD 2300 “Barcelona” Opteron-based servers (attached to a circa 2007 technology SAN) to Exadata. This customer also cited the fact that there is no such thing as “pure OLTP” and since it is a fact I don’t refute it.
Last week I read an interesting article about how cloud computing is changing the role of the enterprise architect and it got me thinking about the bad rap many architects are getting in the brave new agile, cloud, big data world.
From what I’ve been reading, there’s been a bit of a straw man argument going on — enterprise architects are often described as uber-control freaks who attempt to dictate software architectures in a repressive way to implementation teams. Mention the term “reference architecture” and you’ll often raise the hackles of the new developer-led world.
To be sure, there are many enterprise architects who match that description. And they’re the ones who give architects a bad name, just like undisciplined developers can give agile a bad rap too.