System User DBC - Teradata VantageCloud Lake

Lake - Database Reference
Deployment
VantageCloud
Edition
Lake
Product
Teradata VantageCloud Lake
Release Number
Published
February 2025
ft:locale
en-US
ft:lastEdition
2025-11-21
dita:mapPath
ohi1683672393549.ditamap
dita:ditavalPath
pny1626732985837.ditaval
dita:id
ohi1683672393549

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

DBC Space Purpose
PERM Provides ownership of the 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
  • 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, 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 changes in all current sessions and Redo and Undo WAL records.
Stores in the Data Dictionary the definitions for system tables, indexes, macros, triggers, and views.
Provides permanent space for the following:
  • Table headers.

    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 for data inserted into materialized global temporary tables.
SPOOL Provides maximum defined SPOOL space to each user and database for the following uses:
  • Dynamic allocation and release of intermediate and final result sets during query processing.
  • Volatile temporary tables.