All,

As we should prevent users from doing direct (and unsafe) system table
updates, I propose (hoping to be in v2.5) creation of DDL command to
change [NOT] NULL field constraint.

The syntax would be:
alter table <table> alter <field> not null;
alter table <table> alter <field> null;

It's semantics would be:
When putting "NOT NULL", in DFW (commit time) the table is locked
and a BLR dynamic query is constructed to inspect for NULL values. If
there are, we throw an error.


Adriano