Partition Data Files

Partition files are the physical files used to store user objects.

A database file partition is addressable by a number (the value of the number property inherited from the SchemaEntity superclass of the DbFile class) and a unique partition identifier. A partition identifier is a positive integer in the range 1 through 2^32-15 (4,294,967,296 minus 15). This unique identifier remains associated with a partition for the lifetime of the partition.

When a database file has been partitioned, the set of partitions associated with a schema-defined map file is referred to as a partition set. The external file name assigned to a file partition is derived from the schema-defined file name and incorporates the partition number as a qualifier, in the following format.

map-file-name_partpartition-number.dat

An instantiated partitioned file contains at least one partition. The first partition is assigned a partition identifier of one (1) and has the file name map‑file‑name_part0000000001.dat.

Further partitions are assigned numbers 2, 3, 4, and so on up to 2^32-15 (15 instances are reserved). The latest partition created (that is, the partition with the highest assigned number) is the current (or default) partition.