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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

OCP 12C – Emergency Monitoring, Real-Time ADDM

Emergency Monitoring Emergency monitoring is meant for extreme circumstances where it’s impossible for you to connect to the database because the database is hung. Emergency monitoring allows you to connect to the database in diagnostic mode and run a lightweight analysis to see what’s happening. You can access real-time performance data from ASH and access [...]

ORA-20104: create_collection_from_query ParseErr:ORA-00918: column ambiguously defined

Always check out the original article at for latest comments, fixes and updates.

If you are wondering why you are getting this error message after following the example in the documentation describing procedure CREATE_COLLECTION_FROM_QUERYB2 in the APEX_COLLECTION API, the quick answer is that the sample code is flawed.

ORA-20104: create_collection_from_queryb2

Back to Basics With Dbvisit Replicate VI

We are near the end of our journey.  In parts 1-5 (Part I, Part II, Part III, Part IV, Part V) we ran through the complete setup wizard.  In Part V we completed the setup wizard and are now ready to take the final steps to get replication up and running.  We will start by looking at […]

Avro MapReduce Jobs in Oozie

Normally when using Avro files as input or output to a MapReduce job, you write a Java main[] method to set up the Job using AvroJob. That documentation page does a good job of explaining where to use AvroMappers, AvroReducers, and the AvroKey and AvroValue (N.B.

An Introduction to Extended Data Types in Oracle 12c

One of the lesser known new features that comes as a boon to many developers and DBAs is the provision of implicit handling of large data strings using scalar data types like VARCHAR2 and RAW.

When creating tables, each column must be assigned a data type, which determines the nature of the values that can be inserted into the column. Common data types include number, date, and varchar2. These data types are also used to specify the nature of arguments for PL/SQL programs like functions and procedures.

Plan depth

A recent posting on OTN reminded me that I haven’t been poking Oracle 12c very hard to see which defects in reporting execution plans have been fixed.

Dallas Oracle Users Group Performance Meetup

I spoke at a one day DOUG meeting yesterday. It was pretty cool. Very small intimate group of about 50. The speakers were Nitin Vengurlekar, Charles Kim, Cary Millsap and myself. All are Ace Directors and either work at Viscosity or Enkitec. As a bonus, Tanel Poder showed up to weigh in on some open discussion. Anyway, I thoroughly enjoyed it. I promised the group I would post my slides and a zip file with some of my scripts that I demoed. So here it is (click on the image to download a zip file with PDF and scripts):

How to setup git as a daemon

This is a quick post on using git on a server. I use my Synology NAS as a fileserver, but also as a git repository server. The default git package for Synology enables git usage on the command line, which means via ssh, or via web-DAV. Both require a logon to do anything with the repository. That is not very handy if you want to clone and pull from the repository. Of course there are ways around that (basically setting up password-less authentication, probably via certificates), but I wanted simple, read-only access without authentication.

Going dotty – Generating a Filename containing a parameter value in SQL*Plus

As I have alluded to previously, I was not born in the UK.
Nope, my parents decided to up-sticks and move from London all the way to the
other side of the world, namely Auckland.
Then they had me. Then they came back.
To this day, they refuse to comment on whether these two events were related.

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