Partitioning is the database process where very large tables are divided into multiple smaller parts. By splitting a large table into smaller, individual tables, queries that access only a fraction of the data can run faster because there is less data to scan.
Creating a partitioned table or index typically happens in four parts:
- Create a filegroup or filegroups and corresponding files that will hold the partitions specified by the partition scheme.
- Create a partition function that maps the rows of a table or index into partitions based on the values of a specified column.
- Create a partition scheme that maps the partitions of a partitioned table or index to the new filegroups.
- Create or modify a table or index and specify the partition scheme as the storage location.