Error Encountered in Cognos 8.3 with Oracle XE

Below is the error message that I encountered when trying to run a report in Cognos.

CNC-MON-0024 Monitor Service paging error: Listener refused the connection with the following error: ORA-12519, TNS:no appropriate service handler found The Connection descriptor used by the client was: localhost:1521:XE

I am not too sure what is the actual cause of this error but below is the way that I solved it.

Launch SQL Plus and issue the the command as below:

SQL> connect / as sysdba;
Connected.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount;
ORACLE instance started.

Total System Global Area 285212672 bytes
Fixed Size 1287016 bytes
Variable Size 96472216 bytes
Database Buffers 184549376 bytes
Redo Buffers 2904064 bytes
Database mounted.

SQL> alter system set job_queue_process=20;
System altered.

SQL> alter system set PROCESSES=100 scope=SPFILE;
System altered.

SQL> alter system set open_cursors=300 scope=both;
System altered.

SQL> alter database open;
Database altered.

SQL> alter system disable restricted session;
System altered.

Hope this may helps. :)

Install and Configure Cognos 8 Business Intelligence - Part 1

This post shows the step-by-step from installation and configuration of Cognos 8.

Assumption : MS SQL Server 2005 and IIS already installed in your machine.

Install Cognos 8 BI on Windows 2000

Run the issetup.exe in the win32 folder from your download directory. The following screen will be shown.


Ensure that English is selected as the language and click Next.


Accept the license agreement by choosing the I accept radio button. Click Next.


Accept the default as the installation location. Click Next.


A dialog box will be pop-up to ask for confirmation whether you want to create the directory. Click Yes and next screen will be shown.


Ensure that all the components are selected as depicted in above screen and click Next.


Click Next again at this step.


You are now at Installation Summary screen which summarize list of components to be installed in your machine and in the particular drive. Click Next.


The installation process is now starting. Once completed, click Next and you can see the following screen.


Click on finish to close the screen. You just finish with the installation process of Cognos 8 BI.

You shouldn't have any problem with all the steps indicated here as the entire installation process is pretty straight forward. I will be posted the Part 2 end of this week. :)

Hidden pages within Mozilla Firefox

The hidden pages of Firefox are configuration items that allow end users to see and make changes to the way Firefox operates. Let's have a try on it by typing the command in the address field.

1. about: - Shows the about information for the Firefox application. Similar to the usual Help ? About menu option found in most applications (and in Firefox, too).
2. about:buildconfig - Displays platform configuration information used in the running build of Firefox.
3. about:cache - Shows the caching information stored for Firefox.
4. about:plugins - Displays the installed plug-ins running within the current install of Firefox.
5. about:credits - Shows the brains, and the coding brawn behind the Firefox project.
6. about:Mozilla - Displays quotations from the Book of Mozilla.
7. about:config - Modifies configuration parameters used by Firefox
   

Source:Finding the hidden bells and whistles in Firefox by Derek Schauland

Google Browser Sync

Google Browser Sync is a Firefox add-ons that can be used to automatically synchronize your bookmarks, history, persistent cookies and saved password across all the computers where you install it. It also remembers which tabs and windows you had open and when you last closed of your browsers. This allows you to restore open tabs and windows in case you accidentally close it.

Once installed, you will find yourself to go right to the sites that you want without to think for half-a-second on what is the address for the web site. To try yourself, go here.

Slowly Changing Dimension (SCD)

In dimensional data warehouse, most dimensions change over time. When a dimension changes, e.g. when a product get renamed or product get a new category. Therefore we must maintain the dimension history to ensure that old sales orders will still be able to reference after the changes. In order to achieve this, the slowly changing dimension or in short SCD comes into the picture.

SCD is a technique for implementing history maintenance in dimensional data warehouse. In general, there are three types of SCD : SCD Type 1, SCD Type 2 and SCD Type 3. Let's define the types of SCD.

a) SCD Type 1

• Updates dimension records by overwriting the existing data.
• Used when no history of the records is maintained in the table like situation where we directly overwrite the incorrect data.

b) SCD Type 2

• Doesn't delete or modify any existing data.
• Whenever there is a change in source, a newer version of records will be created. This means that it will keep a full history of dimension data in the table.

c) SCD Type 3

• Maintains just previous and current data.
• It keep history by adding more than one column to records to maintain its history. For example, in customer dimension table, we will have two extra columns: Current_Address and Previous_Address.
• Used to maintain a limited history where we have a database space constraint.