Watch Kerry Osborne compare and contrast Hadoop and Exadata Architecture from his E4 2012 presentation “Hadoop Meets Exadata.”

Here’s the Part 2 of the Oracle SQL plan execution hacking session (Part 1 is here)!

We’ll use a bit of DTracing to peek inside an Oracle SQL plan execution, plus some other random experiments. You can download the qer_trace.sh script from here. Note that this is not a “How to use DTrace” webinar, you have to learn DTrace yourself to understand (or enhance) this script.

This is the Part 1 of the hacking session I delivered live.

In this part we’ll talk mostly about how an application talks to the database session when wanting to execute a query (tracing OPI calls, fetch operations etc).

In the Part 2 (which I will upload soon) we’ll drill down inside an execution plan then.

Enjoy!

Here is the link to set up a user account at Enkitec and download Karen’s presentation deck from E42012:

http://www.enkitec.com/about/presentations/tuning_sql_for_oracle_exadata

Here’s the video of Snapper v4.0 beta “launch party”. I have fixed most of the bugs you see in this video

You can get the latest Snapper v4 BETA from here:

• http://blog.tanelpoder.com/files/scripts/snapper4.sql

Please save it with “Save as…”, not copy & paste to an editor, as some editors tend to mess up large pasted content.

You can download most enkitec.tv videos also from iTunes Podcasting system and they tend to have better quality than the web version. Just subscribe to http://blip.tv/enkitectv/rss or search for EnkitecTV in the podcast directory!

I delivered a live Oracle hacking session at OakTableWorld in San Francisco two weeks ago and here’s the video (Thanks to Kyle Hailey & co)!

Note that this was a hacking session deliberately aimed to be fun and “hackerish” rather than useful. Do not try this in your production databases!!!

The title is “Lots of undocumented, unknown and unnecessary features in Oracle!”

You can watch it here:

Note that there are more videos available on OakTableWorld website (and probably more will show up soon!)

Enjoy!

This hacking session’s topic is Oracle parameter infrastructure. We will look into some internals of Oracle instance, session and optimizer environment parameter management. This session does not attempt to explain what all the individual parameters do, but how parameters work in general.

This knowledge can be useful for explaining some seemingly weird things happening in Oracle

1) Did you know that there are multiple different types of configuration parameters inside Oracle?
2) Do you want to know why changing some session parameters causes Oracle to recompile a new child cursor, while some parameters (notably the _small_table_threshold and _serial_direct_read) don’t?
3) Where are the session-level parameter values kept?
4) How to see what Oracle parameters some other session is using at the moment?

NB!!! Note that as the name says, this is a free hacking session – informal, fun and unstructured online hacking with no slides and no particular sturcture – it’s all demos in sqlplus.

Note that I had some trouble with my recording software in the end, so part of the question #2 will be answered in a future video!

(iTunes link)

By the way, I didn’t mention this in the hacking session, but ORADEBUG DUMP PARAMETERS 1 allows you to dump all *modified* parameters of another session (if you connect to that session’s process with oradebug first):

*** 2012-04-12 21:18:41.094
 Processing Oradebug command ‘dump MODIFIED_PARAMETERS 1′
 DYNAMICALLY MODIFIED PARAMETERS:
 timed_statistics = TRUE
 timed_os_statistics = 60
 nls_date_format = dd-MON-yy
 optimizer_index_caching = 11
 _serial_direct_read = ALWAYS
 _rowsource_execution_statistics= TRUE
 _rowsource_profiling_statistics= TRUE
 statistics_level = ALL
 _sqlmon_threshold = 5
 _timemodel_collection = TRUE

Enjoy!