Archive for November, 2009

DOAG Konferenz 2009: Impressions Day 3 (final)

Thursday 19th was the last day of DOAG Confernce 2009. Compared with the second day, the program was much more dense: For my (DBA) profile there have been several hours, where more that one talk would have been appropriate.

This list is, what I collected during the day.

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DOAG Konferenz 2009: Impressions Day 2

As promised, today my impressions of yesterday (confusing, I know). Clarification: This is about Wednesday, November 18th. I’m still at DOAG Conference 2009 in Nuremberg. Wednesday was a silent day for my interests, especially at noon there have been less talks being of interest, but maybe they have done something for my general knowledge…

So once again, this are impressions, a digital copy of my scratchpad, unordered and without warranty. :)

For SQL Trace analysis:

  • let’s look at HOTSOS Profiler by Mr. Milsap, TRCANLZR (Oracle), TV$XTAT, ORASRP and MERTITS Profiler. For the latter, a limited free edition is available (without realtime V$ associations)
  • Review the Index usage when date/timestamp datatypes are used
  • 11g cursor close type (in a trace file) might enlighten something

Oracle on VM:

  • Oracle VM 2.2 uses XEN 3.4 core now
  • nice feature of Oracl VM: IO Priority (time slicing)
  • Oracle DB in an Oracle VM will have about 10% losses on CPU power
  • Oracle VM is limited to 60.000 IOPS :)
  • PVM with Direct Driver option is fastest
  • Activate Direct IO
  • Windows will be faster than on bare metal when running on Oracle VM, due to better IO scheduling

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DOAG Konferenz 2009: Impressions Day 1

These days, the DOAG Conference 2009 happens in Nuremberg, Germany. First day was yesterday, Tuesday November 11th 2009. This is a machine-readable copy of my scratchpad, coming from the different talks I attended.

  • Sun Oracle Database Machine Exadata 2: The “Quarter Rack” (consisting of 2 Servers and 3 storage nodes) sounds interesting.
  • 11gR2 has some features only available with Exadata: For example, a special “Storage Index”, grouping several lines with theit MIN and MAX values in order to minimize scan ranges (called Smart Scan)
  • Exadata provides inter-instance IO ressource management possibilities, it might be useful to look at the IO ressource management capabilities of 11g without Exadata as well!
  • Really interesting stuff was “Righttime Data Warehousing – reducing latency” of Sven Bosinger; his presentation and the paper will be great material to explain some stuff for conceptional discussions. Thanks, Sven!
  • Look at issues for your DB release version! Metalink Note 161818.1 is great for that!!
  • Flashback Data Archive may be a good tool for an archiving concept (Oracle sales tells us about Basel II and stuff), but have care!Firstly, DDL on tables prepared for FDA is slow, and secondly and worse, if you have tablespace quotas on your schema, the archiving might stop if it’s full. And that without error messages due to asynchronous archiving. Only way to monitor that is to scan for new trace files all the time. :(
  • The new Oracle Grid Infrastructure and its Instance Caging sounds interesting as well. Especially the CPU assignment with CPU_COUNT parameter sound nice, as well as CPU overcommitment (assigning more CPUs than you have).
  • Oracle OMotion and RAC One Node are other nice ones: But at the moment, RAC One Node is not available with Standard Edition!

At a glance: The first day was great, and absolutely interesting. Let’s see what Wednesday brings, the program looks promising so far.

Best regards from Nuremberg
Martin Klier



New My Oracle Support (ex. Metalink): Use without flash: HTML Option

In the last days, My Oracle Support was redesigned. But since flash is a performance eater and not always available, people like to have an option to use My Oracle Support (formerly Metalink) with HTML only.

The link to it is well-hidden, but nevertheless useful!

Give it a try: https://supporthtml.oracle.com

Best regards
Usn




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