System User DBC - Teradata Database

Teradata Database Design

Product: Teradata Database
Release Number: 15.10
Language: English (United States)
Last Update: 2018-10-06
Product Category: Software

System User DBC

The PERM space allocation of system user DBC is used for the following:

This DBC space…	Performs this service …	For this function …
PERM	provides ownership	Teradata production database space, which must accommodate the maximum PERM space allocated to each user and database by its creator. The allocated space is used to store the rows in the data tables created by each user, including the following items. Primary data table rows Join index table rows Hash index table rows LOB and XML subtable rows Secondary index subtable rows Optional permanent journal image rows Optional fallback rows, which replicate the rows of primary data tables, index subtables, hash and join index tables, and permanent journals
	creates and maintains the WAL log/transient journal	storing a before-image copy of every row affected by data modifications in all current sessions and Redo and Undo WAL records.
	stores system table, index, macro, trigger, and view definitions	setting up the data dictionary.
	provides permanent space	Table headers. Note that each materialized global temporary table also requires a minimum of 512 bytes from the PERM space of its containing database or user for its table header. CRASHDUMPS database.
TEMP	provides temporary space	data inserted into materialized global temporary tables.
SPOOL	provides maximum defined SPOOL space per creator-defined allocation to each user and database	Dynamic allocation and release of intermediate and final result sets during query processing. Volatile temporary tables.