Found 95 Articles for SQL

Building blocks of a Data Model

Raunak Jain
Updated on 10-Jan-2023 18:34:59
Introduction A data model is a blueprint that represents the organization of data and the relationships between different data entities. It is an essential component of any software system as it defines how data is stored, accessed, and modified. In this article, we will explore the building blocks of a data model and how they work together to form a cohesive whole. Data Entities The first building block of a data model is data entities, which represent the objects or concepts that are relevant to the system. For example, in an e-commerce system, data entities might include products, customers, orders, ... Read More

Building a Data Warehouse

Raunak Jain
Updated on 10-Jan-2023 18:30:45
A data warehouse is a central repository of integrated data that is used for reporting and analysis. It stores large amounts of historical and current data and enables fast query performance for analytical purposes. A data warehouse can be used to support business decision-making, improve operational efficiency, and gain a competitive edge. In this article, we will discuss the process of building a data warehouse from scratch. Understanding the Requirements for a Data Warehouse Before starting the design and construction of a data warehouse, it is important to understand the business requirements and the type of data that will be ... Read More

Sqoop Integration with Hadoop Ecosystem

Nitin
Updated on 25-Aug-2022 12:27:12
Data was previously stored in relational data management systems when Hadoop and big data concepts were not available. After introducing Big Data concepts, it was essential to store the data more concisely and efficiently. However all data stored in the related data management system needs to be transferred to the Hadoop archive. With Sqoop, we can transfer this amount of personal data. Sqoop transfers data from a related database management system to a Hadoop server. Thus, it facilitates the transfer of large volumes of data from one source to another. Here are the basic features of Sqoop − Sqoop ... Read More

Difference between NoSQL and RDBMS

Pradeep Kumar
Updated on 22-Jul-2022 07:42:35
Most SQL databases are relational. Relational Databases are tabular and have a pre-determined schema that organizes the data logically. Database management solutions have evolved from the classic relational paradigm to the more flexible and scalable NoSQL approach.Some say NoSQL stands for "non-SQL, " but many refer to it as SQL. NoSQL is a non-relational database management system for certain data models. These data models don't need a schema and are scalable. It offers a system-supported alternative to relational databases' tabular format for storing and retrieving data. NoSQL databases don't require a certain schema. You can store data without worrying about ... Read More

Floyd's triangle in PL/SQL

sudhir sharma
Updated on 01-Feb-2022 10:59:10
PL/SQL is a combination of SQL along with the procedural features of programming languagesFLOYD’s triangle − it is a triangle formed by natural numbers. It is the triangle formed by filling numbers in rows starting from 1 at the top-left corner. It is a right-angled triangle i.e. the count of numbers in each row is the same as the row number.In this problem, we are given a natural number N. Our task is to create Floyd’s triangle in PL/SQL.Let’s take an example to understand the problemInput: 16 Output: 1 2 3 4 5 6 7 8 9 10 11 12 ... Read More

Finding sum of first n natural numbers in PL/SQL

sudhir sharma
Updated on 01-Feb-2022 10:26:35
In this problem, we are given a number N. Our task is to finding sum of first n natural numbers in PL/SQL.PL/SQL is a combination of SQL along with the procedural features of programming languages.PL/SQL has the following features −PL/SQL is tightly integrated with SQL.It offers extensive error checking.It offers numerous data types.It offers a variety of programming structures.It supports structured programming through functions and procedures.It supports object-oriented programming.It supports the development of web applications and server pages.PL/SQL has the following advantages −SQL is the standard database language and PL/SQL is strongly integrated with SQL. PL/SQL supports both static and ... Read More

Find the area and perimeter of right triangle in PL/SQL

sudhir sharma
Updated on 27-Jan-2022 08:57:10
In this problem, we are given three values: base, height and hypotenuse of a right triangle. Our task is to find the area and perimeter of the right triangle in PL/SQL.PL/SQL is a combination of SQL along with the procedural features of programming languagesLet's take an example to understand the problem, Input : height = 4, base = 3, hypotenuse = 5 Output : area = 6, perimeter = 12Explanation −1 + 22 + 333 + 4444 = 4800 Solution ApproachA simple approach to solve the problem is using the formula for the area and perimeter of the triangle.Area = ... Read More

Difference Between ROLAP and MOLAP

AmitDiwan
Updated on 15-Apr-2021 07:43:12
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

Difference Between View and Materialized View

AmitDiwan
Updated on 15-Apr-2021 07:37:31
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

Difference Between DELETE and DROP in SQL

Kiran Kumar Panigrahi
Updated on 21-Feb-2023 14:11:53
DELETE is a Data Manipulation Language (DML) command. It is used to remove tuples/records from a relation/table. On the other hand, DROP is a Data Definition Language (DDL) command and is used to remove named elements of schema like relations/table, constraints or entire schema. Read this article to learn more about DELETE and DROP commands in SQL and how they are different from each other. What is DELETE in SQL? In SQL, the DELETE command is used to remove some or all the records from a database table. With the DELETE command, the WHERE clause is used to define the ... Read More
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