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December 2011

The Girl With The Dragon Tattoo….

This trilogy of books is awesome. I wrote about them here, here and here. You should definitely read them first.

I initially resisted watching the Swedish films, thinking they would be crappy compared to the books. On the insistence of one of my friends, who watched them after reading the books, I eventually saw them on DVD and they were great. They felt very much like the definitive films of the books to me. You should definitely watch these after reading the books.


l have just added a quick addendum about checking for trace events (and related information) to the Appendix page of Oracle Core.

This item is a temporary note to alert subscribers to the update, and it will be deleted in a few days.

Book Review: Oracle Core Essential Internals for DBAs and Developers

December 25, 2011 (Modified December 29, 2011) Digging Deeply into Oracle Internal Processing when the Oracle Wait Interface is Insufficient I pre-ordered a paperback copy of this book three months ago from Amazon and also purchased a PDF copy of the book from Apress.  It was a long, nearly six year wait since the [...]

Happy Christmas/Holiday

Just a quick post to say happy Christmas to those that celebrate it.

To everyone else, happy holiday. Of course, if you don’t have a holiday this time of year I guess it’s just happy now. :)



Merry Christmas (plus long lost “The Jean Genie”)

I just want to wish you all a very Merry Christmas and a very happy, safe and successful New Year. As always, thank you all so much for supporting the blog, with all your comments and nice feedback. Hopefully, you’ve found content here that has been of some use. Now that I’m back at Oracle [...]

The Transforming Face of the Oracle Support Site

December 23, 2011 A day or two ago I saw an announcement that the HTML (non-Flash) version of the Oracle Support site was to be phased out in January 2012.  It seems like the last time I tried to use that site, the search functionality did not quite work for Oracle Database products; I gave up on [...]

Friday Philosophy – Christmas Cheer and Business Bah-Humbug

For many, today is the last working day before Christmas and the festive season – So I sincerely wish upon everyone a Merry Christmas.. If you don’t celebrate Christmas, well the intent of my wishes still holds – I hope everyone; whether working or not; religious leanings for, against or indifferent; has an enjoyable few days during whatever end-of-year festives you have.

I’m going to be miserably now. You might want to stop reading here and maybe go to the shops for that last spell of retail hell or some other Christmas tradition. It’s probably best if you do…

The mutating table error prevents non-deterministic behavior of your code

A short recap of workarounds 1a and 1b from our previous post.

Extended DISPLAY_CURSOR With Rowsource Statistics


So this will be my Oracle related Christmas present for you: A prototype implementation that extends the DBMS_XPLAN.DISPLAY_CURSOR output making it hopefully more meaningful and easier to interpret. It is a simple standalone SQL*Plus script with the main functionality performed by a single SQL query. I've demoed this also during my recent "optimizer hacking sessions".

DBMS_XPLAN.DISPLAY_CURSOR together with the Rowsource Statistics feature (enabled via SQL_TRACE, GATHER_PLAN_STATISTICS hint, STATISTICS_LEVEL set to ALL or controlled via the corresponding hidden parameters "_rowsource_execution_statistics" and "_rowsource_statistics_sampfreq") allows since Oracle 10g a sophisticated analysis of the work performed by a single SQL statement.