Preprocessing External Tables

A question that comes up now and again is there a way in Oracle Database 11g Express Edition to mimic some behavior in the Oracle Standard or Enterprise editions. Many of these questions arise because developers want to migrate a behavior they’ve implemented in Java to the Express Edition. Sometimes the answer is no but many times the answer is yes. The yes answers come with a how.

This article answers the question: “How (more...)

External Tables

Oracle Database 9i introduced external tables. You can create external tables to load plain text files by using Oracle SQL*Loader. Alternatively, you can create external tables that load and unload files by using Oracle Data Pump. This article demonstrates both techniques.

You choose external tables that use Oracle SQL*Loader when you want to import plain text files. There are three types of plain text files. They are comma-separated value (CSV), tab-separated value (TSV), and position (more...)

Recreate Database Using Only Datafile and Logfile

Let’s have look on the steps are used by Oracle DBA  for “Recreate Database Using Only Datafile and Logfile”.
Backup of the control file in trace

SQL> ALTER DATABASE BACKUP CONTROLFILE TO TRACE;

create password file and service

D:\> orapwd file=D:\oracle\product\10.2.0\db_1\database\PWDdba71.ora password=sys entries=10

D:\> oradim -new -sid dba71 -intpwd sys -maxusers 10 -startmode auto -pfile D:\oracle\product\10.2.0\admin\dba71\pfile\init.ora

set the environment and start the database in nomount

D:\>set oracle_home=D:\oracle\product\10.2.0\db_1
 (more...)

APEX New Workspace

After you install APEX or upgrade a base APEX, you need to create workspaces. These instructions show you how to create a workspace in APEX 18. You have two options, you can use the base url while specifying the INTERNAL workspace.

  1. You start the process by accessing the Oracle APEX through the standard form by entering the following URL:


    http://localhost:8080/apex

    • Workspace: INTERNAL
    • Username:  ADMIN
    • Password:  installation_system_password

  1. The better approach is to use the (more...)

APEX 4 to 18 Upgrade

While preparing my new instance for class, which uses Oracle 11g XE and Fedora 27, I got caught by the Oracle instructions. I should have got caught but when you’re in a hurry sometimes you don’t slow down enough to read it properly. Actually, for me it was the uppercase APEX_HOME that threw me for a moment. It looks too much like an environment variable. Step 5 of the upgrading instructions says:

  1. Log back into (more...)

Index Monitoring in Oracle Database

Applies to ONLY Oracle Database 10gR1 through to 12cR1.
In Oracle Database 12cR2, this feature is replaced.  A new blog post of this feature will be posted in due course.

Since Oracle 10g, you can monitor indexes to see if they are being used or not.  Which is very useful as indexes, consume unnecessary CPU and I/O on DML activity if not used.  Therefore, it’s recommended to monitor indexes and any unused (more...)

Loading Tables with Oracle GoldenGate and REST APIs

With Oracle GoldenGate 12c (12.3.0.1.x), you can now quickly load empty target tables with data from your source database. You could always do this in previous releases of Oracle GoldenGate, but the process has now been simplified using REST APIs and some scripting know-how. In this post, I’m going to show you, high level, how you can use the REST APIs and a bit of scripting to do an initial load (more...)

Adding a Datafile to Temp Tablespace

When monitoring Tablespace Usage (see my Tablespace Usage blog post for more info), there comes a point when you need to add a datafile to the temp tablespace to allow for growth and more importantly get below a monitoring threshold for example in OEM or OpsView.

Query to see Current Temp Datafiles State

To see the current state of the temp datafiles:

set pages 999
set lines 400
col FILE_NAME format a75
select d.TABLESPACE_NAME,  (more...)

RegExp: Constraint to prevent spaces at the beginning or end.

Even though a space is a regular character, the client didn't want spaces at the beginning or end of a string. Any spaces in the middle were fine.
Of course this could be handled by the application, but it must also be implemented in the database. Using a check constraint with a regular expression will prevent the end user from entering unwanted data.

To try things out, let's just start with a simple table with (more...)

Rounding amounts, divide cents over multiple lines

In previous articles I wrote about dealing with a missing cent when you need to divide a certain amount over multiple lines. In these articles, links are at the bottom, I described a method to calculate the difference on the last row.
Then a question arose (as a comment):
What if for example i have 42 records and i wish to divide 100 by 42. I would get a rounded value of 2.38. If (more...)

Rounding Amounts, the missing cent: with the MODEL clause

Rounding amounts may lead to rounding-issues, I have written how this may be resolved in a previous blogpost using some analytic functions.
Playing around a little bit, I also came up with a method to resolve the rounding difference with the MODEL clause.

To create an example, first let's create a table with only three records in it.


SQL> create table t
2 as
3 select rownum + 42 id
4 from dual
5 connect (more...)

Conditional Compilation and Static Boolean

One of my pet-projects is LoggerUtil, which is a utility for Logger, which is an excellent logging tool for PL/SQL.
This post is not about Logger, but some dealings with Conditional Compilation.

With Conditional Compilation you can create a single code base to handle different functionalities depending on compiler flags.
The latest addition to LoggerUtil was a method to create a custom template. For this to work, LoggerUtil depends on a certain Logger Release (where (more...)

Deadlock with a Virtual Column

Virtual Columns are really cool. I like them a lot. If you've never heard of them, shame on you, learn about them.
In short: a Virtual Column is not a real column, it's an expression that looks like a column... more or less.
While using the Virtual Columns, we ran into a little oddity with them.

First of all let's start with the version of the database that I tested this on. Yes, I know (more...)

Creating Database Using DBCA Silent Mode

Creating database using DBCA silent mode? Learn how to provision a database in a non-interactive mode.

The post Creating Database Using DBCA Silent Mode appeared first on VitalSoftTech.

Splitting a comma delimited string the RegExp way, Part Three

The article read most often on this blog is called "Splitting a Comma Delimited String, the RegExp way".
On this blog there are two articles about this technique, one is about splitting up a single string into multiple rows and the other is about multiple strings into multiple rows.
Links to both articles are included at the bottom of this article.
It seems like there is a need for functionality like that frequently. And just (more...)

Want to SPEED Up Your Database Tasks? DBMS_PARALLEL_EXECUTE to the rescue!

Use DBMS_PARALLEL_EXECUTE to divide one huge task into multiple small tasks that can be executed at the same time. See how many ways are there to divide.

The post Want to SPEED Up Your Database Tasks? DBMS_PARALLEL_EXECUTE to the rescue! appeared first on VitalSoftTech.

Configure Oracle Exadata Write Back Flash Cache

In addition to improving read I/Os, Oracle Exadata Write back flash cache also provides the ability to cache write I/Os directly to PCI flash. Exadata storage software version 11.2.3.2.1 is the minimum version required to use write back flash cache. Grid infrastructure and database homes must run 11.2.0.3.9 or later to use with Write-back Smart […]

The post Configure Oracle Exadata Write Back Flash Cache appeared first on VitalSoftTech.

Oracle Database 10g Certifications to Expire in March 01, 2015

Oracle Database is one of the leading relational database management system and is used all over the world. It has various training’s, exams and certifications for its Database and other products. However due to regular update in Database, they have to redesign their trainings, certification and exams to add new features and to remove old […]

The post Oracle Database 10g Certifications to Expire in March 01, 2015 appeared first on VitalSoftTech.

Free e-book giveaway: “Oracle Database XE 11gR2 Jump Start Guide” (Packt Publishing, 2012)

Last week I reviewed “Oracle Database XE 11gR2 Jump Start Guide” (Packt Publishing, 2012) in this post. Packt guys did like the review, and today I am pleased to announce that I will be giving away two free e-copies of the book. All you need to do is just comment below the post and win [...]

Book review: “Oracle Database XE 11gR2 Jump Start Guide” by Asif Momen

About a year ago Packt Publishing approached me and offered to write a book on (one of the technologies in) Oracle 11g. After careful consideration I had to decline the offer. Which was the right decision as I have hardly had any spare time in the past 12 months. However, Packt guys have kept in [...]