A method for maintaining high availability for an on-line database which
includes: creating a first user account having a plurality of first
tables and first schema objects; creating a second user account having a
plurality of second tables and second schema objects; creating a third
user account having a first set of synonyms for the first tables and
first schema objects; creating a fourth user account having a second set
of synonyms for the second tables; accessing the first user account using
the first set of synonyms; modifying data using the second set of
synonyms into the second user account to provide a plurality of revised
second tables and revised second schema objects; dropping the first set
of synonyms; creating a third set of synonyms in the third user account
for the plurality of revised second tables and revised second schema
objects; and accessing the second user account using the third set of
synonyms.