Restrictions on fragmentation expressions
The following restrictions apply to the expression:
- Each fragment expression can contain columns only from the current table, with data values only from a single row.
- The expression must return a BOOLEAN (true or false) value.
- No subqueries, aggregates, user-defined routines, nor references to fields of a ROW type column or sequence objects are valid.
- The built-in CURRENT, SYSDATE, TODAY, SITENAME, DBSERVERNAME, CURRENT_USER, or USER functions are not valid.
- The DEFAULT_ROLE and CURRENT_ROLE operators are not valid.
The columns contained in the fragment expression for unique indexes must be the same as the indexed columns or a subset of the indexed columns.
The restrictions listed above also apply to indexes that use a LIST fragmentation strategy.