In the RDBMS world, data modeling has principles around tables, columns, data types, size, and so on, and the only supported format is structured data. HBase is quite different in this aspect, as in each row, it can store different numbers of columns and data types, making it ideal for storing so-called semi-structured data. Storing semi-structured data not only impacts the physical schema but also the logical schema of HBase. For the same reason, some features such as relational constraints are also not present in HBase.

Similar to a typical RDBMS, tables are composed of rows and these rows are composed of columns. Rows in HBase are identified by a unique rowkey and are compared with each other at the byte level, which resembles a primary key in RDBMS.

In HBase, columns are organized into column families. There is no restriction on the number of columns that can be grouped together in a single column family. This column family is part of the data definition statement...