Subject Re: [firebird-support] FB 2.1.2.18118 bug in system table?
Author Dimitry Sibiryakov
> However, the system table RDB$RELATION_FIELDS in the column
> RDB$NULL_FLAG this item is NULL, not 1!

And it means that value from RDB$FIELD.RDB$NULL_FLAG is in effect.

SY, SD.