Adaptive STAT lines in SQL trace

Lately I’ve been using SQL runtime execution statistics combined with SQL monitor for performance diagnostics and, honestly, almost forgot about SQL trace. So this note is not very useful to me but it might be to someone: along with ALL_EXECUTIONS option appeared in (I believe) 11gR2, there’s a new option starting with which can significantly decrease amount of data in the trace files for STAT lines compared to ALL_EXECUTIONS, still providing some of them from time to time.

Here is a case to demonstrate:

    n number := 0;
    dbms_session.session_trace_enable(true, true, 'all_executions');
    for x  (more...)

Universidade do Porto nos 10 primeiros lugares europeus no webometrics

| Jul 30, 2012
A Universidade do Porto está de acordo com o ranking da Webometrics no 8º lugar europeu e em 69º mundial (julho 2012). No ranking, também de presença web , "4 International Colleges & Universities" está em 180º lugar mundial e 49º europeu (2012). No ranking (não web) "Academic Ranking of World Universities" encontra-se entre os lugares 168-204 europeus e 401-500 mundial (dados de 2012 a serem anunciados em agosto). No "Times Higher Education World University Rankings" 2011-12, está no lugar 301-350 mundial. No QS Top Universities está no 401-450 mundial (na área de Engenharia (more...)

Mutex waits. Part III. Contemporary Oracle wait schemes diversity.

Several months have passed since my previous “mutex wait” post. I was so busy with work and conference presentations. Thanks to all my listeners at UKOUG2011, Hotsos2012 and Medias2012 conferences and several seminars for inspiring questions and conversations. I. Unexpected change. Now it is time to discuss how contemporary Oracle waits for mutexes. My previous [...]

Building a Simple Chat Application with Active Data Service and JSF2 AJAX in Oracle ADF

Data push with Active Data Services (ADS) in Oracle ADF has been available for some years. AJAX functionality has got attention in JSF2 specification. JSF2 made its way into ADF with JDeveloper Release2. This blog post provides a simple ADF active Chat application, built by using active data service functionality (more...)

Buffer is pinned count


There are many cases where Oracle revisit some buffer in the buffer cache many times inside one database call. It such cases it can pin the buffer and hold the buffer pinned and just read pinned buffer in consequences visits. It allows to avoid redundant logical reads.

There are statistics “buffer is pinned count” and “buffer is not pinned count”.
The concept is simple: there is the function kcbispnd (“Kernel Cache Buffer Is Pinned” as I suggest) where Oracle checks if a buffer is pinned or not. If a buffer is pinned then statistic “buffer is pinned count” (more...)

Digger: the tool for tracing of unix processes

I would like to introduce new tool – Digger.
This tool allows to see tree of process’ calls such as application calls, library, system calls (and even kernel functions and OS scheduler actions) with additional information as function arguments, result, cpu & elapsed time.
This is not something Oracle specific, the tool can be used for tracing of any unix process (DTrace is required).


Looping synonyms and transportable

Whilst doing an export as part of TTS

> expdp directory=tmp_dir dumpfile=test_meta.dmp transport_tablespaces=tts_conv

Export: Release - 64bit Production on Thursday, 31 May, 2012 11:03:50

Copyright (c) 2003, 2007, Oracle. All rights reserved.

Username: / as sysdba

Connected to: Oracle Database 10g Enterprise Edition Release - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options
Starting "SYS"."SYS_EXPORT_TRANSPORTABLE_01": /******** AS SYSDBA directory=tmp_dir dumpfile=test_meta.dmp transport_tablespaces=tts_conv
ORA-39123: Data Pump transportable tablespace job aborted
ORA-01001: invalid cursor
ORA-06512: at "SYS.DBMS_SYS_SQL", line 902
ORA-06512: at (more...)

AIA Tips & Tricks Series: Purging ESB Resequencer Tables in AIA 2.5 (Example: Comms PIPs)

AIA 2.5 Comms PIPs use the ESB 10g Resequencer for the following ESB Services:

  • CommunicationsCustomerPartyEBSV2Resequencer
  • SyncAcctSiebelAggrEventConsumer_RS
  • ProcessSalesOrderFulfillmentSiebelCommsSequencer
  • Consume_UPDSO_RS

While processing extensive volumes, the number of rows can grow quite rapidly in the ESB Resequencer tables (ESB_MESSAGES, ESB_MESSAGE_MAP, ESB_GROUP_STATUS). It is therefore critical to include these tables in the regular (more...)

R12 Federal Financials Subledger Accounting Teardown Webinar, 10-Aug, 9:00am ET

OAUG has invited me to present as part of their upcoming Best of COLLABORATE ’12 Educational Series.  I’ll be delivering the R12 Federal Financials Subledger Accounting Teardown presentation via Webinar on Friday, August 10th, starting at 9AM EDT.  This presentation is a deep-dive into most of the key SLA concepts that support the R12 Federal Financials SLA accounting engine.  My goal is to share what I’ve learned through 1 1/2 years of supporting one of the most complex Federal R12 upgrades to-date, now live for 5+ months.

Here’s the presentation agenda:

This is free for all OAUG (more...)

Oracle Database 12c – New Feature: Identity Columns

Well, Oracle Database 12c is not yet available but new features seems to be popping out in MOS. While troubleshooting Oracle Enterprise Manager Cloud Control 12c startup issues I came across Oracle Database 12c new feature called “Identity Columns”.

An Identity Columns is auto-incremented at the time of insertion just like in SQL Server. Going forward, I think you will not use Oracle Sequence anymore to generate unique values instead use Identity Columns.

For more information on this read:

Happy reading!!!

InteliVideo is Ramping Up!

The rubber is starting to meet the road now!  We're getting some serious traction in the market wiith InteliVideo.  J.P. O'Brien, a long time friend has joined me as a co-founder and CEO.  We're signing up customers each week.  We have customers in 3 different categories: 1) Long tail videos - just like Amazon was originally focused on the long tail books, we're focused on the long tail video market.  2) Mid tail videos - these are our ideal customer who have videos.  These companies have the best potential for knocking it out of the park with a viral (more...)

VMware: Maritz out, Gelsinger in. What does it mean for Oracle?

As many of you have heard by now, Paul Mauritz is out as CEO of VMware, and Pat Gelsinger (formerly COO of EMC, reporting directly to Joe Tucci) is replacing him.

The relevant question for those of us who care passionately about Oracle virtualization using VMware vSphere is:

What does this mean for VMware's BCA (Business Critical Applications: stuff like Oracle) strategy (which under Maritz was somewhat lacking)?

In my view, this is very, very good news indeed. The reason is simple: Paul Maritz was former Microsoft, and thus very Microsoft-centric. Under Maritz, VMware very successfully penetrated the Microsoft (more...)

Oracle licensing on VMware: Exceptional Michael Webster blog post

As my comment on Michael Webster's recent blog post entitled Fight the FUD – Oracle Licensing and Support on VMware vSphere states, I am in violent agreement with everything he says regarding Oracle licensing and support for VMware virtualization of Oracle database servers. I heartily recommend this blog post to everyone concerned with Oracle's recent behavior regarding VMware virtualization of their products.

SOA Suite 11g advanced training experiences

Read my report from Oracle Fusion Middleware Summer Camps in Munich: SOA Suite 11g advanced training experiences.


We all know deadlock is the situation where DBA cannot do anything and directly can be blamed on application saying – this is an application issue. Oracle writes the same in its trace file of deadlock. 

The following deadlock is not an ORACLE error. It is a deadlock due to user error in the design of an application or from issuing incorrect ad-hoc SQL.

I agree to above but we, DBA can help application developer in determining cause of the deadlock. Here are some samples to check the clause of the deadlock.

It is very important to analyze the deadlock graph especially (more...)

When will my rebalance complete

This has to be one of the top ASM questions people ask me. But if you expect me to respond with a number of minutes, you will be disappointed. After all, ASM has given you an estimate, and you still want to know when exactly is that rebalance going to finish. Instead, I will show you how to check if the rebalance is actually progressing, what phase it is in, and if there is a reason for concern.

Understanding the rebalance

As explained in the rebalancing act, the rebalance operation has three phases - planning, extents relocation and compacting. (more...)

Quotable Quotes

It started with a tweet from Tim O’Reilly. He mentioned a quote that I’m very familiar with – “Data matures like wine, applications like fish”. When I read it I wondered if it was anything to do with. His tweet linked to a blog post called the 11 best data quotes from the DataMarket blog. On that list (which I highly recommend reading) the quote was tentatively attributed to me based on a write up of my 2009 OSDC presentation entitled “Change Bad!”.

I’d like to take the credit for this, I really would. But I can’t. I did (more...)

Um patch para o SQL Navigator 6.7

| Jul 20, 2012
Para quem usa o SQL Navigator 6.7 e tem notado que "às vezes" prende, tal parece ter origem na "feature History" que guarda os SQL (tec..) efetuados e permite uma pesquisa nos mesmos. É possivel efetuar uma "limpeza dos comandos efetuados" antes de uma data data ou toidos de modo a evitar que o ficheiro fique muito grande (parece que apartir de 600K é que o problema é encontrado) "Before you deleting your history file, you can have a backup if needed, the history file is in: xp: C:\Documents and Settings\UserName\Application Data\Quest Software\SQL Navigator 6.6.0\Unified (more...)

Pointless, Incessant Barking

This cartoon speaks to why I’ve begun blogging again.  

It goes like this, when you blog about a completed project have to encapsulate it, describe it, explain it, and learn from it. Otherwise you just push projects out the door and move on. As my old ad agency boss (more...)

Don’t forget about column projection

Note: this post is not about some exact statement, but about importance of column projection which should not be ignored, especially in cases as operations requiring workareas, data access optimization, Exadata offloading and others.

Let’s consider merge of two simple tables.

 merge into t1
 using t2 on ( =
  when matched 
  then update set n = 1;

The tables:

SQL> select * from v$version where rownum = 1;
Oracle Database 11g Enterprise Edition Release - 64bit Production

SQL > create table t1 compress
  2             as
  3         select rownum as id,