Category and shared subclass both are different terms. Their concepts are separate fields from each other. The category contains two or more superclasses which may represent different-different entity types, while other regular shared subclasses always have a single superclass. An entity that is a member of the shared subclass must exist in all superclasses, but … 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: The difference between the database system and file system are as follows: Sl no. Database management system File management system 1. A DBMS is a collection of data. It does not require users to write procedures. A file system is a collection of data. In this, users need to write procedures. 2. It is … 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. There are two types of cursor Implicit cursor: It is a predefined cursor that is associated with DML hence the declaration is not required in this cursor. Some … 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
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
Granularity is the size of data items that are allowed to lock. There are three types of lock granularity Course granularity: It is used to lock tables, files, databases, and records. It reduces the transaction number and decreases the throughput to increase the response time of the transaction. But this also causes the concurrency to … Read more
The optimistic control protocol is also called validation-based protocol which copies the transaction data locally and updates the local copy of data instead of actual data in the database. It works in three phases Read phase: All transaction data are read and stored in a temporary variable which is also called the local variable of that … Read more