Tables Area: User TEMP Space Requirements
The TEMPORARY clause in the CREATE DATABASE and CREATE USER statements permits you to allocate default space within this database or user for inserting data into global temporary tables materialized by users. Note that Teradata Database always reserves temporary space prior to spool space for any user defined with this attribute.
Disk usage for a materialized global temporary table is charged against the temporary space allocation of the user who referenced the table.
Global temporary tables also require a minimum of 512 bytes from the PERM space of the containing database or user. This space is used for the GTT table header.
If no default temporary space is defined for a database, then the space allocated for any global temporary tables created in that database is set to the maximum temporary space allocated for its immediate owner.
Subtract the TEMP amount allocated to this database.