Author Archives: user

SQL – Composite Key Table of content The SQL Composite Key An SQL Composite Key is a key that can be defined on two or more columns in a table to uniquely identify any record. It can also be described as a Primary Key created on multiple columns. Composite Keys are necessary in scenarios where […]

SQL – Alternate Key Table of content The SQL Alternate Key SQL Alternate Keys in a database table are candidate keys that are not currently selected as a primary key. They can be used to uniquely identify a tuple(or a record) in a table. There is no specific query or syntax to set the alternate […]

SQL – Non-Clustered Index Table of content SQL Non-Clustered Indexes The SQL Non-Clustered index is similar to the Clustered index. When defined on a column, it creates a special table which contains the copy of indexed columns along with a pointer that refers to the location of the actual data in the table. However, unlike […]