In the case of any database, whether it is RDBMS or NoSQL, we always need to find out the record size in order to plan the storage size needed, or to in order do a capacity planning. Even a few bytes per record might bring drastic changes to the data storage size that we estimate. For example, suppose we have one extra byte attached to each record, and we have around one billion records, and this extra byte requires around 1 GB of storage space on the disk.

Now, let's consider this data size calculation in case of HBase. Let's consider a table named employee, where we have fields such as the row key, the column family, the column, and the value. In HBase, each value is stored as fully qualified, so for each column of a record, it is accompanied with the row key we assign. So, let's now consider the space requirement.

As HBase stores data in the key-value format, let's now do the approximation. We will consider the row key as student1.