If you create an auto-incremented column or a sequence attached to a column, and then decide to change the target DBMS various transformations will be effected.
DBMS change |
Defined in original DBMS |
Effect on sequence objects and auto-incremented columns |
---|---|---|
DBMS supporting sequences to a DBMS supporting auto-incremented columns |
Sequence attached to a column |
The sequence disappears and the column to which it was attached becomes an auto-incremented column in the DBMS |
DBMS supporting auto-incremented columns to a DBMS supporting sequences |
Auto-incremented column |
The auto-incremented column is deleted and replaced by a sequence object called S_TABLENAME which is attached to the original column |