Parallel DML

A recent posting on OTN presented a performance anomaly when comparing a parallel “insert /*+ append */” with a parallel “create table as select”.  The CTAS statement took about 4 minutes, the insert about 45 minutes. Since the process of getting the data into the data blocks would be the same in both cases something was clearly not working properly. Following Occam’s razor, the first check had to be the execution plans – when (more...)

Partner news: Red Stack Tech rebranding to provide services for the entire Oracle Technology stack

Specialised Oracle Platinum Partner, Red Stack Tech have had their application to trademark their rebranded company name, 'Red Stack Tech' approved. The Oracle specialist company went through a rebrand in 2015 seeing its company name change from e-DBA to Red Stack Tech.

The rebrand to Red Stack Tech symbolises how far the company has grown from a remote database organisation in 1998 to a global organisation providing services across the entire Oracle Technology stack and (more...)

Installation von Hybrid Cloud Agenten – Quick Guide

Datenbanken, die in der Oracle Cloud im Rahmen von Database as a Service betrieben werden, können von Ihrer lokalen Cloud Control Umgebung verwaltet werden. Dazu müssen Sie in der Oracle Cloud die Agenten in den dort laufenden virtuellen Maschinen installieren. Dieser Tipp gibt Ihnen einen schnellen Einstieg in dieses Thema.

Het innovatieproces – strategisch of tussen wal en schip?

Door Joost Maliepaard, Solutions Director Retail, Distribution and Manufacturing

Over het belang van innovatie is de afgelopen tijd veel geschreven. Het
midden- en kleinbedrijf benoemde strategie en innovatie zelfs als prioriteit nummer 1 voor 2016. Ook uit onderzoek van PwC blijkt dat CEO’s innovatie als topprioriteit omschrijven.

Helaas gelooft
slechts 20 procent van deze CEO’s dat de investeringen zich voldoende terugverdienen. De conclusie van het onderzoek: het loont om het innovatieproces te borgen met een (more...)

EM13c: How to Disable Autodiscovery (and Autopromotion) of Clusterware Managed Targets

After we upgraded EM13c, I encountered a problem about automatically promoted listener targets. Since EM12c, I do not add/promote listeners. In earlier versions of EM12c, I had weird problems while monitoring listeners on RAC systems (such as they are detected down although they’re up). Since then, I don’t monitor them (specially SCAN listeners). In EM12c, when I remove a listener, it doesn’t promoted again. With EM13c, I see that listeners are discovered and promoted automatically (more...)

HCM Data Loader (HDL) – Objects Supporting Deletes

Here is a list of most commonly used objects during HDL conversion and if they support deletes or not. You can review HDL user guide for the complete list of supported objects. 

Delete command - You can use the DELETE action as part of the HDL (.dat) file for objects supporting deletes. Command identifies business-object components to be purged from Oracle Fusion HCM. You cannot delete individual date-effective records so you need to (more...)

Data Visualizations FAQ and New Data Visualization Articles on the JET Blog

Check out the latest data visualization articles on the Oracle JET Blog!

The Data Visualization FAQ provides pointers to answers to many questions about DVT components, such as which visualizations to use for which data sets, best practices, and more.

For our ADF and MAF customers, here are some very relevant articles that will help you with the common issues across the frameworks:

1. Which visualization should I use for percentage data sets?

Blog article: (more...)

An UNDO in a PDB in Oracle 12c?

 

According to the Oracle 12cR1 documentation and concepts, it is 100% clear that there can be only one UNDO tablespace in a multitenant architecture and it is at CDB level; thus, a PDB cannot have any UNDO tablespace.

Are we really sure about that? Let’s test it!

First, we need a PDB with few tablespaces:

 

FRED_PDB> select NAME, OPEN_MODE, CON_ID from v$pdbs ;

NAME OPEN_MODE CON_ID
-------------------------------------------------- ---------- ----------
FRED_PDB READ WRITE  (more...)

Expert Insights: Oracle NET Troubleshooting for DBAs

 

Troubleshooting connection issues with Oracle SQL*Net can be difficult at times due to the many options that can be taken during configuration. One of the options is where the file tnsnames.ora may be found. There are multiple locations available, and at times there is justification for having more than one copy of the file.

Perhaps there is a hybrid database naming configuration. Say there are a number of company-wide databases that are defined (more...)

Exadata onecommand fails at cell disk creation

I was installing another Exadata last month when I got an error on create cell disks step. I’ve seen the same error before when I was extending two to three rack Exadata configuration but thought it was one-off.

The cell disk creation failed as below:

[root@exa01db01 linux-x64]# ./install.sh -cf Customer-exa01.xml -s 8

 Initializing
 Executing Create Cell Disks
 Checking physical disks for errors before creating celldisks.........................
 Restarting cell services....................................................
 ERROR:

 Stopping the RS, CELLSRV,  (more...)

Hinting

This is just a little example of thinking about hinting for short-term hacking requirements. It’s the answer to a question that came up on the Oracle-L listserver  a couple of months ago (Oct 2015) and is a convenient demonstration of a principle that can often (not ALWAYS) be applied as a response to the problem: “I can make this query work quickly once, how do I make it work quickly when I make it part (more...)

Amazon Web Services (AWS) : Relational Database Services (RDS) for Oracle

Here’s the latest video on my YouTube channel. This one is a quick run through of RDS for Oracle, a DBaaS offering from Amazon Web Services.

If you are not into the video thing, you can see the article this video was based on here.

Galo Balda has now joined the illustrious list of people who have said “.com” on one of my videos. :)

(more...)

The Data Warrior Speaks 2016: Updated

As expected, I have been booked to speak a few more places this year. Here is my updated speaking schedule as of today: RMOUG Training Days 2016 – February 9-11 in Denver, CO (I have 2 hour deep dive on Feb 9th). Register here. TDWI Nashville – March 8th in Nashville (of course). I will be […]

Partitioned Bitmap Join

If you don’t want to read the story, the summary for this article is:

If you create bitmap join indexes on a partitioned table and you use partition exchanges to load data into the table then make sure you create the bitmap join indexes on the loading tables in exactly the same order as you created them on the partitioned table or the exchange will fail with the (truthful not quite complete) error: ORA-14098: index (more...)

Pareto Rocks!

I'm a big fan of Vifredo Pareto's work.  He observed the world around him and developed some very simple concepts to explain what he observed.  Pareto was ahead of his time.

Some of Dr. Pareto's work is based on the Pareto Principle:  the idea that 80% of effects come from 20% of causes.  In the real world, we continually see examples of the Pareto Principle.

I've been conducting one of my informal surveys (more...)

Log Buffer #458: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers various useful tips and tricks from blogs for Oracle, SQL Server and MySQL.

Oracle:

  • pstack(or thread stack) for Windows to diagnose Firefox high CPU usage
  • With the ever-changing browser landscape, we needed to make some tough decisions as to which browsers and versions are going to be deemed “supported” for Oracle Application Express.  There isn’t enough time and money to support all browsers and all versions, each with (more...)

Lex de Haan

Today marks the 10th anniversary of Lex de Haan passing away. Although 10 years is a long time, I think about my dear friend Lex at least once a week. Lex assisted me adapting to new teaching skills when I progressed to blindness. It was Lex his idea to use colored magnets on my classroom […]

PROCESSED Messages not clearing from Oracle Queue

I was contacted by Dev team to look into Development database where Oracle queue size kept  on increasing. As per them messages were not getting cleared.They were running count on Queue table and the count kept increasing. To find out exact cause I included the msg_state in the query and found out that there were…

OT: YesSQL Summit 2016 Picture Diary

YesSQL Summit 2016 sponsored by O'Reilly and Axxana was held by the Northern California Oracle Users Group on January 26–28 at the Oracle conference center in Redwood City, California in conjunction with BIWA Summit 2016 and Spatial Summit 2016. The grand raffle prize sponsored by O'Reilly was a full pass to Strata + Hadoop World on March 28–31 in San Jose, California. Save 20% on Strata + Hadoop World conference passes with discount code UGNOCOUG. (more...)

Multisessioning with Python

I'll admit that I pretty constantly have at least one window either open into SQL*Plus or at the command line ready to run a deployment script through it. But there's time when it is worth taking a step beyond.

One problem with the architecture of most SQL clients is they connect to a database, send off a SQL statement and do nothing until the database responds back with an answer. That's a great model when (more...)