Technical Articles

Technical Oracle Articles

Hash join anti vs Nested loop join anti

This post shows you details about a specific case where 'hash anti join' is defeated by 'nested loop anti join'.
The initial problem came to light in a very large BW system running on Oracle when several BW loads (making use of older data in the BW system) reported missing dimension ids in the dimension tables.

Software Review - Stellar Phoenix Oracle Database Recovery Software

The demand of Oracle database is very high and because of high demand, its security becomes the most concerned part of its users. Backup is the initial process you can do for your database security. However, at times, taking backup is also not sufficient and issues like backup file corruption, database damage due to virus, etc. takes place and data loss occurs. Therefore it's always better to have a utility to repair your damaged or corrupt Oracle Database Files and reconstruct its objects.

Oracle DBA interview Questions

So many fresher Oracle DBAs and intermediate Oracle DBAs are searching online Oracle DBA interview Questions but unfortunately they are getting older and theoretical questions about Oracle basics. If you will prepare yourself from those content then you might get trouble to crack technical interview.

GoldenGate replication

I have tried the GoldenGate Software for data replication. I would like to share the steps to one who is really looking for Goldengate replication steps.

I feel its a simple if we think it is simple, If we think its complicated, it is really a complicated. Start with a mindset that you can achieve it.

Oracle 12c new feature: Flex Clusters, what they are (and what they are not)

I have seen articles that misrepresent a Flex Cluster, even this book Expert Oracle RAC 12c which is written by people who know better (Oracle ACE directors, an OCM, an Oak Table member) gets it wrong, because of a reliance on beta documentation.

How to generate your test case automatically

One often sees requests for test cases, typically when a user has a SQL performance issue. So many users appear to have problems with producing a suitable test case that Uncle Oracle provides routine to automate this. There are no longer any excuses for not providing a test case. Here is an intro to how to do it (code tested on and


In this post, I will demonstrate a new feature introduced in 12c : In database archiving. It enables you to archive rows within a table by marking them as invisible. This is accomplshed  by means of a hidden column ORA_ARCHIVE_STATE. These invisible rows are not visible to the queries but if needed, can be viewed , by setting a session parameter ROW ARCHIVAL VISIBILITY.


-- Create test user uilm, tablespace ilmtbs
-- Connect as user uilm
-- create and populate test table (5 rows) ilmtab with row archival clause


When you create a PDB, the database automatically creates and starts a service inside the CDB.The service has the same name as the PDB. It is possible that the name of the service will collide with an existing service name which is registered with the same listener. For example if two or more CDBs on the same computer system use the same listener, and the newly established PDB has the same service name as another PDB in these CDBs, then a collision occurs.

You must not attempt to operate a PDB that causes a collision with an existing service name.

Top 12 New Features of Oracle 12c Summarized

Top 12 Features of Oracle 12C Summarized. This article is also available at
Summary: The Oracle 12C means different things to different people. It all depends on which areas you are looking at, as there are improvements in many areas. Summarized below is the list of Top 12 Features of Oracle 12C as I see it. I have summarized below, the top 12 which I found interesting.

About Apps 11i Clone – A Human Touch

Apps clone is like cloning a human being. Please read the detail below.

1) Run adpreclone on DB/CM/AP tiers

This is pre-requisite step of cloning 11i prod and will not change anything in any system. This script will only create on $COMMON_TOP, a directory called "clone", with a basic structure of executable, scripts, templates and java files. Later to the creation of the clone directory, the process picks up important information of your source system with which upgrades the necessary templates for the process adcfgclone that was carried out in the target server.


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