Browsed by
Tag: Complete Notes on Database Management System

Can you explain the between clause

Can you explain the between clause

Below SQL selects employees born between ’01/01/1975′ AND ’01/01/1978′ as per mysql SELECT * FROM pcdsEmployee WHERE DOB BETWEEN ‘1975-01-01’ AND ‘2011-09-28’ Sure, the BETWEEN clause in a database management system (DBMS) is used to specify a range to test against. It’s commonly used in SQL queries to filter data within a specified range of values. Here’s how it works: sql SELECT column_name(s) FROM table_name WHERE column_name BETWEEN value1 AND value2; column_name: The column you want to test against. table_name:…

Read More Read More

What are Fact tables and Dimension Tables ? What is Dimensional Modeling and Star Schema Design

What are Fact tables and Dimension Tables ? What is Dimensional Modeling and Star Schema Design

When we design transactional database we always think in terms of normalizing design to its least form. But when it comes to designing for Data warehouse we think more in terms of denormalizing the database. Data warehousing databases are designed using Dimensional Modeling. Dimensional Modeling uses the existing relational database structure and builds on that. There are two basic tables in dimensional modeling:- Fact Tables. Dimension Tables. Fact tables are central tables in data warehousing. Fact tables have the actual…

Read More Read More

About RDBMS

About RDBMS

RDBMS It exhibits all relationships. It is very easy to manage the data. In RDBMS data is stored in tabular form. Tables have rows & columns. Rows represent records and column represents fields. To access the data in RDBMS “SQL (Structured Query Language)” is used. Limitations of RDBMS: 1. It is slow as compare to network RDBMS. 2. Redundancy of data to establish the relationship between tables. Different types of RDBMS: ORACLE, SQL Server, Sybase, DB2, MySQL, etc. SQL queries…

Read More Read More