Schema name restrictions and recommendations

There are some restrictions and recommendations that you must be aware of when naming schemas.

• User-defined types (UDTs) cannot have schema names longer than the schema length listed in SQL and XML limits.
• The following schema names are reserved words and must not be used: SYSCAT, SYSFUN, SYSIBM, SYSSTAT, SYSPROC.
• To avoid potential problems upgrading databases in the future, do not use schema names that begin with SYS. The database manager will not allow you to create modules, procedures, triggers, user-defined types or user-defined functions using a schema name beginning with SYS.
• It is recommended that you not use SESSION as a schema name. Declared temporary tables must be qualified by SESSION. It is therefore possible to have an application declare a temporary table with a name identical to that of a persistent table, in which case the application logic can become overly complicated. Avoid the use of the schema SESSION, except when dealing with declared temporary tables.