DBMS - Data Independence

• 
• 

PrevNext

If a database system is not multi-layered, then it becomes difficult to make any changes in the database system. Database systems are designed in multi-layers as we learnt earlier. Data Independence A database system normally contains a lot of data in addition to users’ data. For example, it...

Continue reading

What Is Oracle Database?

• 
• 
• 
• 

PrevNext

What is a database A database is an organized collection of structured data stored electronically in a computer system. When the computer was first invented, it was mainly used for scientific researches to perform calculation quickly. Since the computer was adopted more and more, the requirements were also...

Continue reading

HTML with Embedded Images from PL/SQL

• 
• 

PrevNext

◉ Background The IMG tag allows you to include images in HTML. Typically you see this with the source containing a URL, as shown below. <img src="http://oracle-base.com/images/site_logo.gif" /> Using a URL in the tag means the browser (or email client) must make a separate HTTP request to get...

Continue reading

DBMS - File Structure

• 
• 

PrevNext

Relative data and information is stored collectively in file formats. A file is a sequence of records stored in binary format. A disk drive is formatted into several blocks that can store records. File records are mapped onto those disk blocks. File Organization File Organization defines how file...

Continue reading

DBMS - Data Backup

• 
• 

PrevNext

Loss of Volatile Storage A volatile storage like RAM stores all the active logs, disk buffers, and related data. In addition, it stores all the transactions that are being currently executed. What happens if such a volatile storage crashes abruptly? It would obviously take away all the logs...

Continue reading

UTL_CALL_STACK : Get Detailed Information About the Currently Running Subprogram in Oracle Database 12c

Oracle database 12c introduced the UTL_CALL_STACK package to allow programmatic access to the call stack and error stack, giving much greater flexibility for debugging and error handling of PL/SQL code. This is only a replacement for the existing functionality if you need the extra level of control. The...

Continue reading

SQL - Database Tunning

It takes time to become a Database Expert or an expert Database Administrator. This all comes with lot of experience in various database designs and good trainings. But the following list may be helpful for the beginners to have a nice database performance − ◉ Use 3BNF database design...

Continue reading

DBMS - Data Recovery

• 
• 

PrevNext

Crash Recovery DBMS is a highly complex system with hundreds of transactions being executed every second. The durability and robustness of a DBMS depends on its complex architecture and its underlying hardware and system software. If it fails or crashes amid transactions, it is expected that the system...

Continue reading

Data Guard Physical Standby Setup Using the Data Guard Broker in Oracle Database 19c

Data Guard is the name for Oracle's standby database solution, used for disaster recovery and high availability. This article gives an example of the setup and administration of Data Guard using the Data Guard Broker. ◉ TL;DR If you already know about Data Guard and want to quickly...

Continue reading