SQL Joins: Inner Join Vs Outer Join
In Relational Database, more often than not, related data is distributed along multiple tables.
So when we need to retrieve a set of data stored along multiple tables, we have to retrieve the data from all the related tables and combine them, and we do this by using the common factor in those tables.
It happens at times that when data gets repeated in a table and it would not be convenient to store repeated data.
Not only it will take extra space, but also it could lead to update/delete anomalies and thus having inconsistent or redundant data.
Continue reading here:
By: Piu Mallick