In a Database Management System (DBMS), “instance” and “schema” are two fundamental concepts that are as essential as the foundation and blueprint of a building. Let’s explore these concepts in a way that’s easy to understand. What is Instance? Storing data collection in a database at a particular moment in time is called an instance. … Read more
Data redundancy is a situation in which there are multiple copies of the same data stored at different places in the database. For example: When a customer came to a shop to buy something, and shop owner notes down the list of item every time and generate a bill for each product. Then this is … Read more
Ans: What is Database System? A Database System is a complex and sophisticated system designed to store, manage, and retrieve structured data efficiently. It provides a systematic and organized method of storing data in tables that consist of rows and columns. These systems allow for the definition of data types, relationships among different data items, … Read more
A file system is a traditional way for the collection of data and a system that is used to manage data in our system. When there is no word like “database management system (D.B.M.S)”, people use file management systems to store their data. In the file system, we face lots of issues such as searching, … Read more
A cursor is a working area where an SQL statement is executed. It is used to process individual rows returned by the database system for a query. Types of cursor Based on their scope and usage Based on their functionality and behavior Detailed Explanation 1. Explicit Cursors Explicit Cursors are declared by programmers in their … Read more
PL/SQL stands for procedural Structures query language which is an extension of the structural query language (SQL) and oracle relation database. It is independent of the operating system environment and tightly integrated with SQL. It provides extensive error checking, numerous data types, and a variety of programming structures. It also supports structural programming through the … Read more
Oracle stores the definition of data along with the data. This data definition meant the data about the data i.e. Information about the users, table, columns, concerns, and all objects created in the database. This information is stored in the form of a table which is called a data dictionary. The data dictionary is a … Read more
The various oracle processes are listed and explained below Log Writer Background Process (LGWR): This component writes the redo entries from redo log buffers when the user executes the commit statement or the buffer exceeds 1/3rd of the redo log buffers. Database Writer Background Process(DBWR): This component will write all the dirty blocks whenever checkpoints … Read more
Undo/Redo is a database transaction log for handling transaction crash recovery. This algorithm stores all the values and changes made during transactions in a separate memory in case of failure or crash. It utilizes the stored value to restore the loss due to failure. This algorithm is a combination of two approaches UNDO: It stands … Read more
Multiple granularity is a database locking technique that allows various data items of different sizes and set locks on them and also defines the hierarchy of data granularity where small granularities are nested within the larger granularity. There are three types of lock granularity Course granularity: It is used to lock tables, files, databases, and … Read more