John Watson's blog
I have seen articles that misrepresent a Flex Cluster, even this book Expert Oracle RAC 12c which is written by people who know better (Oracle ACE directors, an OCM, an Oak Table member) gets it wrong, because of a reliance on beta documentation.
In earlier releases, running a shell script from the Scheduler was awkward. Oracle has realized this, and introduced a new job type in 12c that makes it simple.
One often sees requests for test cases, typically when a user has a SQL performance issue. So many users appear to have problems with producing a suitable test case that Uncle Oracle provides routine to automate this. There are no longer any excuses for not providing a test case. Here is an intro to how to do it (code tested on 22.214.171.124 and 126.96.36.199).
The inverted table format can deliver fast and flexible query capabilities, but is not widely used. ADABAS is probably the most successful implementation, but how often do you see that nowadays? Following is a description of how to implement inverted structures within a relational database. All code run on Oracle Database 12c, release 188.8.131.52.
There are three restrictions on indexing and partitioning: a unique index cannot be local non-prefixed; a global non-prefixed index is not possible; a bitmap index cannot be global. Why these limitations? I suspect that they are there to prevent us from doing something idiotic.
I see posts on Oracle related forums about various releases (anything that isn't 11.x or 12.x) being "unsupported". This is wrong. Of course you should upgrade any 9i or 10g databases, but you don't have to.
The COST column cannot be used to compare execution plans. Punkt.
Matthew Morris (who makes many constructive and knowledgeable contributions to the forum) has written a series of study guides for the OCA/OCP exams. I asked him if I could have a copy of one to review. The result: it's very good. This is a copy of the review I put up on Amazon.
The other day, I was asked how to move a table from one schema to another. The answer, as we all know, is "you can't do that: you have to create a new table as a copy of the old one, or use export/import. It will take a long long time." Not true.
I've been asked by the publishers to review "Oracle Database 11g Release 2: Performance Tuning Tips and Techniques" by Richard Niemiec of TUSC. Conclusion: it is good but not perfect. This is an extended version of the review I put up on Amazon.