Partition mapping involves the division of large logical tables into smaller physical tables; this division is based on a definable data level, such as month or department. Partitions improve query performance by minimizing the number of tables and records within a table that must be read to satisfy queries issued against the warehouse. By distributing usage across multiple tables, partitions improve the speed and efficiency of database queries.
Time is the most common category for partitioning databases. Partitioning by time limits growth of the database tables and increases stability.