Column boundaries for edit and validation procedures
Db2 stores columns contiguously, regardless of word boundaries in physical storage, except LOB and XML columns. LOB or XML values are not stored contiguously; an indicator column is stored in a base table in place of the LOB or XML values.
You
cannot specify edit procedures for any table that contains a LOB column.
You cannot define edit procedures as WITH ROW ATTRIBUTES for any table
that contains a ROWID column. In addition, LOB values are not available
to validation procedures; indicator columns and ROWID columns represent
LOB columns as input to a validation procedure.
Similarly,
you cannot specify edit procedures as WITH ROW ATTRIBUTES for any
table that contains an XML column. XML values are not available to
validation procedures. DOCID and XML indicator columns represent XML
columns as input to a validation procedure.