IT Tutorials For beginners

How to download and install the right version of SQL Server Express and SQL Server Management Studio Express ?

2015-06-19T04:37:00.000-07:00

Introduction to SQL Server Express Edition

SQL Server is one of the most popular Database Management Systems (DBMS).

It is a limited edition of SQL Server brought to you by microsoft for free.

The version is limited and it should not be used in the production phase.

So, it is manned to be used by students and people who are trying the DBMS before installing the production versions.

The caracteristics of the Express edition are the followings:

Maximum database size of 10 GB per database in SQL Server 2014, SQL Server 2012, and 2008 R2 Express
No SQL Server Agent service
Hardware-utilisation limits:

Single physical CPU, but multiple cores are allowed
1 GB of RAM (uses only 1 GB of RAM independantely of the amount of RAM that you have)

Download SQL Server Express Edition 2014

The links below are for SQL Server 2014 Express Edition with Tools. This download provides both SQL Server Express Edition and SQL Management Studio.

To download SQL Server 2014 Management Studio alone, please use these links

To download SQL Server 2014 Express Edition with Advanced Services, please use these links

Download SQL Server Express Edition 2012

The link below is for SQL Server 2012 Express Edition with Tools. This download provides both SQL Server Express Edition and SQL Management Studio.

SQL Server 2012 Express x64

To download SQL Server 2012 Management Studio alone, please use these links

Download SQL Server Express Edition 2008 R2 SP2

The link below is for SQL Server 2008 SP2 Express Edition with Tools. This download provides both SQL Server Express Edition and SQL Management Studio.

To download SQL Server 2012 Management Studio alone, please use these links

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Download and install Oracle Express Edition

2015-06-16T12:06:00.002-07:00

Introduction To oracle Express Edition

Oracle Company created a free version of Oracle DBMS called Oracle Express Edition.

This version is not for commercial use and it is created for students and developers who are trying

the Oracle DBMS.

The current version of Oracle express edition is: Oracle Database Express Edition 11g Release 2

This version is released on June, 4 2014.

Oracle Company made a version of Oracle DBMS Express Edition for each platform and here we

will give a direct link for each platform and the steps to follow in order to download the right version

for each platform.

We cite some limitations of the Oracle 11g Express Edition:

The maximum data storage supported is 11GB
The maximum RAM size supported is 1GB even if the amount of available RAM is more than that
The database will use only the equivalent of 1 CPU

How to download Oracle DBMS Express Edition

We present here two alternatives

Checking the latest version of Oracle DBMS Express Edition:

The steps to follow to download Oracle Express Edition are the following:

Visit this website
Check the Accept License Agreement radio button
Once the radio button is checked in step 2), you can download the right version for your platform

Direct links to Oracle DBMS Express Edition 11g Release 2 (21/06/2015)

a. For 32 bits windows platform choose this link

b. For 64 bits windows platform choose this link

c. For 64 bits Linux platform choose this link

There is no version for the Mac platform.

How to completely deinstall Oracle DBMS in Windows System

2015-05-27T03:43:00.002-07:00

The deinstallation steps of Oracle DBMS

In the past I've had many problems uninstalling all Oracle products from Windows systems. Here's my last resort method:

Uninstall all Oracle components using the Oracle Universal Installer (OUI).
Run regedit.exe and delete the HKEY_LOCAL_MACHINE/SOFTWARE/Oracle key. This contains registry entires for all Oracle products.
If you are running 64-bit Windows, you should also delete the HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/Oracle key if it exists.
Delete any references to Oracle services left behind in the following part of the registry (HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Ora*). It should be pretty obvious which ones relate to Oracle.
Reboot your machine (otherwise you will still see Oracle service in Control Panel -> Administration Tools -> services).
Delete the "C:\Oracle" directory, or whatever directory is your ORACLE_BASE.
Delete the "C:\Program Files\Oracle" directory.
If you are running 64-bit Wiindows, you should also delete the "C:\Program Files (x86)\Oracle" directory.
Remove any Oracle-related subdirectories from the "C:\ProgramData\Microsoft\Windows\Start Menu\Programs\" directory.
Empty the contents of your "C:\temp" directory.
Empty your recycle bin.

At this point your machine will be as clean of Oracle components as it can be without a complete OS reinstall.

For more details, please see this video.

Learn Network Simulator 3

2015-05-25T09:47:00.003-07:00

The network simulator 3 is a powerful simulator which uses programming best practices and implement accurate network models.

So, it is an interesting simulator to learn.

You can preorder your version of the book: An Introduction to Network Simulator 3 from Amazon right now and take benefit of this powerful network simulator.

If you want to use NS2, please check Book 1 and otherwise check Book 2.

A helpful presentation for NS3 can be downloaded from here.
NS2 common problems and solutions can be downloaded from here.
A helpful on-line presentation for NS3 can be found here. (please, use the arrows buttons in your keyboard to browse the presentation)
Book 1:

Book 2:

Optimise the memory usage of Oracle DBMS on windows plateform

2015-05-24T16:15:00.001-07:00

When installing Oracle on Windows, the oracle DBMS 's services will be configured as automatic.

That means that whenever the computer boots, these services are started even when you are not using Oracle.

To solve this problem, you should go through these steps:

Step 1: Open configuration panel

Step 2: Open Administration tools

Step 3 : Open Services

Step 4 : Search Oracle services which are started

For Oracle 10g: the names of the services contains the string "ORCL"
For Oracle 11g: the names of the services contains the string "XE"

Step 5: Make those services as manual

Right click on the service name then you click on properties

The screen below will appear.

You change the status type to Manual and you click on apply.

Then you click on OK.

Step 6: Whenever you want to use Oracle
For Oracle 10g: start the services "OracleServiceOrcl" and the Oracle listener that contains the string "Orcl"
For Oracle 11g: start the services "OracleServiceXE" and the Oracle listener that contains the string "XE"

To start a service, right click on it and choose start.

How to create console application with Code::Blocks

2015-05-24T10:58:00.000-07:00

After installing code:blocks and launching it you will obtain the corresponding display:

The area (1) allows to do the following tasks:

search a word in the opened file
copy, paste, cut
save the current file or all the files in the project

The area (2) displays the opened projects
The area (3) contains the opened file or a list of projects that you have recently opened

Remarks:
The code::blocks project is a folder that contains many source files and only one .cbp file.
The .cbp file contains metadata used by code::blocks to open the project.

The area (4) displays build messages in the build log tab, search results and debugging stuff.

The button build: compiles source files (.c) into a .o files
The button execute: executes the currently present executable, so if you have a problem with the precedent executable and when using this button the problem persists.

The button build and run: deletes the current executable and generates a new one.I advice you to always use this button to be sure that your modifications are taken into account.

In order to create a console application, you click on File -> New -> console Application

Then you select the C language:

Select the folder where you will save your project:

The folder which contains the project is: C:\Users\Mateo\Projects\

Click on Finish and you are done.

How to download the right version of Code::Blocks

2015-05-24T07:18:00.003-07:00

To download Code::Blocks you should visit this link.

Once you go to this website, you should choose the right version for your plateform.

Here we present the direct links to the executables for the principal Operating systems.

For Windows plateform :

You should pay attention to download the Code::Blocks version which contains the GCC compiler whose name is MINGW.

Choose the version called: codeblocks-13.12mingw-setup.exe

The direct link for this version is the here.

This version works well for the 32 bits and the 64 bits windows plateforms as well.

For Debian plateform : Example: Ubuntu linux distribution belongs to Debian plateform.
The executable files in Debian distributions has the .deb extension.
You should choose the stable version which is located in this address:

There is no version for debian plateform whose architecture is 64 bits.

For Mac OS X plateform :

The direct link to the Mac OS X version is this.

NOTES:

Code::Blocks for Mac is currently not as stable as are other ports, especially on Mountain Lion. In other words, we could use an extra Mac developer (or two) to work on Mac compatibility issues.
We offer a Mac version, explained hereby:
- CodeBlocks-13.12-mac.zip: default release, in ZIP format
The provided download contains an Application Bundle (for the i386 architecture) built for Mac OS X 10.6 (and later), bundling most Code::Blocks plugins.
For older versions please check here