Working with Tablespaces

Tablespaces help optimize data file and work file storage and retrieval. Tablespaces define location definitions that map data artifacts, such as aggregate views and aggregations, to files. Each application directory contains directories for four tablespaces:

Tablespace names are case-sensitive, regardless of operating system. You cannot change the location or size of metadata and log. For default and temp you can specify multiple locations and sizes, and you can define tablespace properties:

Note:

You can modify or delete file locations used to store information within a tablespace if the locations are empty.

Because Tablespace Manager allocates disk space in fixed-size increments, specifying the maximum disk space for a tablespace location specifies an end point but does not reserve the specified space.

When space is needed, Essbase checks file locations (in numerical order) and, when space is found, starts writing. When all locations are used, no space is available, and an error is returned. When database values are cleared, tablespace files shrink, releasing disk space. Work files that are no longer needed are deleted, making space available for other programs.

Based on the maximum size specified for files, Essbase writes multiple files; for example, ess00001.dat, ess00002.dat, and so on. If you back up database files to other media, do not set a maximum tablespace file size greater than the size that the media can handle.