Designing tables

In HBase, when modeling the schema for any table, a designer should also keep in mind the following, among other things:

• The number of column families and which data goes to which column family
• The maximum number of columns in each column family
• The type of data to be stored in the column
• The number of historical values that need to be maintained for each column
• The structure of a rowkey

Once we have answers, certain practices are followed to ensure optimal table design. Some of the design practices are as follows:

• Data for a given column family goes into a single store on HDFS. This store might consist of multiple HFiles, which eventually get converted to a single HFile using compaction techniques.
• Columns in a column family are also stored together on the disk, and the columns with different access patterns should be kept in different column families.
• If we design tables with fewer columns and many rows (a tall table), we might achieve O(1) operations but also compromise with...