How to unlock hr schema in oracle express edition


Unlocking HR Schema in Oracle 10g

For working with oracle database tables you need to install oracle database and unlock
the sample HR schema from your installed version of oracle database.

Here I am going to describe steps and screenshots to unlock the HR schema.

step 1 : After installing oracle database go to the database homepage and login with system  and password.

                            



step 2: After login you can see screenshot page in this page you have to go Administrator link.





step 3: Click on Administrator select Database Users.


step 4: After that go to Manage Users and select manage users.

step 5: Here you can see inside the Manage Users there is HR which is locked click on HR.


step 6:  By default HR user Account status is locked just type the password and select unlocked in account status.


step 7: After that click on Alter User  and you can also set user privileges by selecting Roles.




And you have unlocked the HR schema and now you can connect HR with SQL*Plus or from sql developer.

Introduction to SQL

SQL stands for Structured Query Language which is used to access the database,manipulate the databases.

Structured query language(sql) is:

  • The ANSI(American National Standard Institute)standard for operating relational databases.
  • Efficient,easy to learn and use
  • SQL is set of statements with which all programs and users access data in Microsoft sql database or in oracle database
  • Querying data
  • Inserting,updating,and deleting rows in a table
  • Creating replacing,altering,and dropping objects
  • Controlling access to the database and its objects
  • Guaranteeing database consistency and integrity 
SQL unifies all of the preceding tasks in one consistent language and enables you to work with data at a logical level.

SQL commands:

SQL commands to interact with Relational Databases are CREATE,SELECT,INSERT,UPDATE,DELETE and DROP,commands can be classified into groups based on their nature.

DML - Data Manipulation Language:

CommandDescription
SELECTRetrieves certain records from one or more tables
INSERTCreates a record
UPDATEModifies records
DELETEDeletes records

DDL - Data Definition Language:

CommandDescription
CREATECreates a new table, a view of a table, or other object in database
ALTERModifies an existing database object, such as a table.
DROPDeletes an entire table, a view of a table or other object in the database.

DCL - Data Control Language:

CommandDescription
GRANTGives a privilege to user
REVOKETakes back privileges granted from user

Oracle 11g step-by-step Installation


This are the steps of Oracle 11g installation guide that covers a typical installation scenario with screenshots.






You can purchase and download oracle Database 11g from the official website of Oracle from clicking  Download


1. Select installation method
Following two installation methods are available:
  • Basic Installation – Select this to perform the full Oracle Database 11g installation with standard configuration options. You can use only file system for storage in this option.

  • Advanced Installation – This gives your full control over the installation, including the ability to choose Automatic Storage Management. Select this option as shown below.


2. Specify Inventory directory and credentials
Enter the following information:
  • Enter the inventory directory: /u01/app/oraInventory
  • Specify operating system group name: oinstall


3. Select Installation Type
Following three installation types are available:
  • Enterprise Edition – Select this option.
  • Standard Edition
  • Custom

   
4. Specify Install Location
Enter the following information:
  • Oracle Base: /u01/app/oracle
  • Name: Oracle_Home
  • Path: /u01/app/oarcle/product/11.1.0


5. Prerequisite Checks
In this screen, the Installer verifies that your environment meets all of the minimum requirements for installing and configuring the products that you have chosen to install. You must manually verify and confirm the items that are flagged with warnings and items that require manual checks.
6. Select Configuration Option
Following three configuration options are available:
  • Create a Database – Select this option.
  • Configure Automatic Storage Management (ASM)
  • Install Software Only

7. Select a Database Configuration
Following three database configuration options are available.
  • General Purpose/Transaction Processing
  • Data Warehouse
  • Advanced

8. Specify Database Configuration
Enter the following information:
  • Global Database Name: devdb.example.com . An Oracle database is uniquely identified by a Global Database Name, typically of the form “name.domain”
  • SID: devdb

9. Specify Database Configuration Details
There are four different tabs in this screen as shown below:
  • Memory Tab
    • Select the check-box to Enable Automatic Memory Management
    • Drag the bar to allocate the memory. This will automatically allocate memory size for SGA and PGA depending on the total database memory allocated.
  • Character Sets Tab. Following three character set options are given in this tab.
    • Use the default
    • Use Unicode (AL32UTF8)
    • Choose from the list of character sets.  Select Database Character Set as Unicode standard UTF-8AL32UTF8 – Select this option.
  • Security Tab – Just leave the defaults in this tab.
  • Sample Schema Tab – Just leave the defaults in this tab.

10. Select Database Management Option
Following two management options are available:
  • Use Grid Control for Database Management
    • Management Service: Choose an agent.
  • Use Database Control for Database Management- Select this option.
    • Select the check-box to Enable Email Notifications
    • Outgoing mail (SMTP) Server:
    • Email Address:

11. Specify Database Storage Option
Following two storage options are available:
  • File System – Select this option.
    • Specify Database File location: /u01/app/oracle/oradata/
  • Automatic Storage Management. ASM simplifies database storage administration and optimizes database layout for I/O performance.

12. Specify Backup and Recovery Option
Enable automated backup as shown below. If you’ve configured ASM, you can choose to store the automated backups on ASM. If not, select File System option.


13. Specify database schema password
Enter the password for sys, system, sysman, dbsnmp schemas. You have the option of either using the same passwords or different password for all the accounts in this screen.
14. Privileged Operating System Groups
Enter the following information in this screen:
  • Database Administrator (OSDBA) Group: dba
  • Database Operator (OSOPER) Group: dba
  • ASM administrator (OSASM) Group: dba
15. Oracle Configuration Manager Registration
You can associate your configration information with your metalink account as shown below.

16. Summary Screen
This will display a summary of all the installation option you’ve selected so far. Click on Install to complete the installation.




Linux Operating System Installation and Configuration

How To Install Red Hat Linux Step by Step Guide

Linux operating system are open source pre-eminent of all the Linux OS is the Red Hat Linux, owned and distributed by the Red Hat Inc.You can get this from the official website of  Red Hat.

This post has been formulated as a step-by-step guide to ensure that everybody can install and use Red Hat Linux seamlessly and with ease. 


Step 1 – Insert the Red Hat Linux DVD into the DVD-drive of your computer. As soon as the following screen pops up, press ‘Enter’ to install Red Hat Enterprise Linux (RHEL) through GUI mode.


Step 2- RHEL installer would then prompt you conduct a check as to whether the CD media from which you’re installing is functioning correctly or not. Choose ‘Skip’, press enter and the installation would begin.


Step 3- Next, we need to select the language- English or any other language as per your preference, and then press ‘Next’


Step 4- In this step, the RHEL installer would ask you about the appropriate type of keyboard for the system. We take the ‘US English’ keyboard, you can pick any other option depending on the type of your keyboard. Then press ‘Next’ to move to the next step.

Step 5- Next, the installer would ask for an ‘installation number’ if you wish to install full set of Red Hat functionalities. Enter the installation number and press ‘OK’ if you have an officially licensed installation number(for corporate clients that buy Red Hat’s backup support and full features).
Others can select ‘Skip entering installation number’ and press ‘OK’ to proceed. RHEL would show a warning message, press ‘Skip’ in it to continue.

Step 6- The Red Hat installer would then require you to create partitions in your computer’s hard disk for the installation. You can do it in four ways but the simplest way is to select ‘Use free space on selected drives and create default layout’ as this option will not affect any other OS residing in your system.Check the ‘review and modify portioning layout’ to create partitions and click next.


Step 7- In this step you must create the required system partitions and mount points such as ‘/boot’, ‘/home’, ‘swap’ etc which are required for the Linux’s proper functioning.
To create different partitions such as /home, /var etc, click on ‘New’ to create the partitions.

Then, select /home in the mount point and choose ‘ext3’ as the file system and give the desired size for it and then click ‘OK’. Similarly also create /boot and /var.

Also, create a swap partition by clicking on ‘New’ and then choosing the filesystem as ‘swap’ and also give the size of Swap partition.(Usually size of swap partition SHOULD BE twice the size of RAM available to the system but you can keep its size less than that too)

Once you have made all the desired partitions and given their mount points, click ‘Next’ to continue installation.

Step 8- This step pertains to the default OS that will be loaded by the GRUB loader

(Note- If you have multiple Operating Systems installed, you would see multiple options here and you have to check in front of the OS name that you want to be loaded by default when the system is started.)
Click ‘Next’ to continue.
Step 9- This step pertains to the network settings of the Linux system that you are going to install. You can select the Ethernet devices through which the system would communicate with other devices in the network.You can also provide the hostname, Gateway address and DNS address to the system during this step. (However it’s better to adjust these settings once the system has been fully installed).

Step 10- The next step is to adjust the system clock to your particular time zone. Select your time zone and then click ‘Next’.

Step 11 – This is a very important step that deals with the root(super-user) password for the system . Type the password and confirm it and then click next.

Step 12 – The RHEL installer would then prompt you about if you wish to install some extra ‘Software Development’ or ‘Web Server’ features. By default, keep it at ‘Customize later’ and press ‘Next’.

Step 13- This next step will initiate the installation of Red Hat Linux, press ‘Next’ to begin the process.

Step 14- Upon the completion of installation you should the following screen. Press Reboot and you’d be ready to use your newly installed Red Hat Linux OS.

POST INSTALLATION CONFIGURATIONS
1. Accept the Red Hat License agreement and click ‘Forward.


2. The next step is regarding the configuration of the Firewall. You can Enable or Disable the firewall according to your preferences and then click ‘Forward’.

3. Next step is about the configuration of another security tool- SE Linux. By default you should keep it ‘Disabled’ unless you’re working with very secure information.

4. You can also choose to configure the Kdump, that stores information about system crashes if your system fails but uses valuable disk space. By default don’t enable it.

5. Next, adjust the time and date settings, and then click ‘Forward’.

6. The next step is for software updates from Red Hat, at this point you should skip the registration and register at a later time and then click ‘Forward’.

7. This step is to create a non-admin user for the system. Enter the details and click ‘Forward’.

8. This step is about configuration of your Sound Card, choose a sound device and then click ‘Forward’.

9. Click ‘Forward’ to complete the configurations and start using your Red Hat Linux OS.

Hat Linux OS is now all installed and configured, ready to be used. Good luck using and exploring various features of Red Hat Linux.