Temporary Table Declaration and the Optional SESSION Schema Qualifier
The DBMS Server supports two syntaxes for declaring and referencing global temporary tables:
With the SESSION Schema Qualifier
If the DECLARE GLOBAL TEMPORARY TABLE statement defines the table with the SESSION schema qualifier, then subsequent SQL statements that reference the table must use the SESSION qualifier.
When using this syntax, the creation of permanent and temporary tables with the same name is allowed.
Without the SESSION Schema Qualifier
If the DECLARE GLOBAL TEMPORARY TABLE statement defines the table without the SESSION schema qualifier, then subsequent SQL statements that reference the table can optionally omit the SESSION qualifier. This feature is useful when writing portable SQL.
When using this syntax, the creation of permanent and temporary tables with the same name is not allowed.
Note: In both modes, a session table is local to the session, which means that two sessions can declare a global temporary table of the same name and they do not conflict with each other.
Note: Syntaxes cannot be mixed in a single session. For example, if the table is declared with SESSION the first time, all declarations must use SESSION.