15.00 - System User DBC - Teradata Database

Teradata Database Design

prodname
Teradata Database
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

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.