Definition for how many bytes are to be allowed by default for creating materialized global temporary tables by users within this database. The number of bytes can be an integer, decimal, or floating point value.
The space used by a global temporary table (table header only) is allocated from the PERM space of the database or user where the global temporary table resides. A CREATE GLOBAL TEMPORARY TABLE request creates table header for the table on each AMP, so the database or user must have adequate PERM space to accommodate the global temporary table header on each AMP. Table header size varies by table definition and the maximum size for a table header can be up to 1 Mbyte.
The space used by the materialized temporary table (table header plus possible data row) is allocated from the login user's temporary space. To materialize a temporary table, the user must have adequate temporary space on each AMP to accommodate the materialized temporary table header and the data row (if the AMP owns the row). Note that the user inherits temporary space from its immediate owner if temporary space was not specified when the user was created.