What is USB?A Universal Serial Bus (USB) is a communication interface that allows devices to communicate with a host controller such as a computer system. It links peripheral devices including digital cameras, mice, keyboards, scanners, printers, media players, flash drives, and external hard drives to a computer.A USB may be used for a multitude of things, including providing electrical power, which is why the USB has replaced an array of interfaces like the parallel and serial ports.USB ports are used to connect peripheral devices to computers in a variety of ways.USB 1.xIt is an external bus standard that supports up ... Read More

Memory is a part of any computer system that is used to store data and instructions. Computer memory is broadly classified into three categories − Primary Memory, Secondary Memory, and Cache Memory. Primary memory is usually in the form of random access memory (RAM) and is used to store data that the CPU needs to access quickly. Secondary memory is usually in the form of hard drives, solid-state drives, or removable storage devices (such as USB drives) and is used to store data that the CPU does not need to access immediately. Read this tutorial to find out more about ... Read More

In this post, we will understand the difference between Stack and HeapStackIt is a linear data structure.Memory is allocated in a contiguous (continuous) block.The memory for a stack is allocated and deallocated automatically using the instructions of the compiler.It costs less to build and maintain a stack.It is easy to implement.It is fixed in size; hence it is not flexible.Its only disadvantage is the shortage of memory, since it is fixed in size.If all the blocks are not occupied, memory gets wasted too.It takes less time to access the elements of a stack.It has an excellent locality of reference.HeapIt is ... Read More

A program is a passive entity that has a set of codes and instructions required to accomplish a task. A process, on the other hand, is an active entity of a program that is started with the execution of the program. Thus, the process is started by the program, once it is executed. The instructions of the program are then executed by the process. Read through this article to find out more about programs and processes and how they are different from each other. What is a Program? A program is a set of instruction codes that has been designed ... Read More

In computer systems, different types of memory devices are used to store data permanently. Both SSD and HDD are such storage devices. SSD and HDD are the most commonly used types of secondary memories. HDD is a traditional storage device, while SSD is a modern storage device. SSD and HDD are quite different from each other. The most fundamental difference between SSD and HDD is that SSD (Solid State Drive) is a storage device that stores data in integrated circuits, whereas HDD (Hard Disc Drive) is a device that stores data magnetically. There are several other differences between SSD and ... Read More

In Database Management Systems (DBMS), the ways of designing databases at physical, logical, and view levels are referred to as Data Models. There are two popular data models− the ER Model and the Relational Model. The fundamental difference between the ER Model and the Relational Model is that the ER Model is an entityspecific data model, while the relational model is a table specific model. Read this article to find out more about the ER Model and the Relational Model and how they are different from each other. What is ER Model? ER Model, short for Entity Relationship Model, is ... Read More

In this post, we will understand the difference between trigger and a procedure.TriggersIt is implicitly invoked when an event such as INSERT, DELETE, and UPDATE occurs in a table of a database.Nesting of triggers can be achieved using a table.A trigger can’t be called or defined inside another trigger.Transactional statements such as ‘COMMIT’, ‘ROLLBACK’, ‘SAVEPOINT’ can’t be used in triggers.They are used to maintain referential integrity.This is done by keeping a record of the activities performed on a table.No values are returned in a trigger.No value can be passed as a parameter to a trigger.Syntax to define a trigger:CREATE TRIGGER ... Read More

In this post, we will understand the difference between ROLAP and MOLAP.ROLAPIt stands for Relational Online Analytical Processing.It is used for large volumes of data.The access time in ROLAP is slow.It stores data in the form of relation tables.The data in ROLAP is fetched from a data warehouse.It uses complex SQL queries.A static multidimensional view of the data is created in ROLAP.MOLAPIt stands for Multidimensional Online Analytical Processing.It is used for less/limited volumes of data.The access time is quick in MOLAP.Data is stored in a multidimensional array.Data is fetched from the MDDBs database.A sparse matrix is used in MOLAP.Dynamic multidimensional ... Read More

In this post, we will understand the difference between a view and a materialized view.ViewsIt is a logical and virtual copy of a table that is created by executing a ‘select query’ statement.This result isn’t stored anywhere on the disk.Hence, every time, a query needs to be executed when certain data is needed.This way, the most recently updated data would be available from the tables.The tuple/result of the query doesn’t get stored.Instead, the query expression is stored on the disk.The query expression is stored, due to which the last updated data is obtained.They don’t have a storage/update cost associated with ... Read More

Both data warehouses and data marts serve the same purpose; they are data repositories. However, we can differentiate a data warehouse from a data mart on the basis of the amount of data they can store. A data warehouse a large repository of data that is collected from different organizations, whereas a data mart is a logical subset of a data warehouse. Read this article to find out more about data warehouses and data marts and how they are different from each other. Let's start with a basic overview of the two. What is a Data Warehouse? Data Warehouse is ... Read More