It is a well-known fact that a significant share of the
cost of information systems is spent on maintenance. Some
researchers estimate this share to be around 80% of the
lifetime cost of information systems. A significant share
of adaptive maintenance work of a business information
system starts from a change in the data models it is based
on. Since, almost all business information systems are
based on relational databases, it is clear that relational
database schema changes account for a significant share of
the total maintenance cost. This is aggravated by the fact
that a change in database schema has the potential of
driving existing applications out of date. Modifications to
such applications cost a considerable of time and money to
business organisations.
Possible solutions to minimize the costs associated with
this problem are essentially technical in nature. This
dissertation explores a couple of possible solutions in
relational database technology, which could help
organisations to keep their system maintenance cost under
check. The main solutions explored are in the area of data
model patterns and schema evolution. A new branch of schema
evolution called “Non Disruptive Schema Evolution” is
explored as well.
It is a well-known fact that a significant share of the
cost of information systems is spent on maintenance. Some
researchers estimate this share to be around 80% of the
lifetime cost of information systems. A significant share
of adaptive maintenance work of a business information
system starts from a change in the data models it is based
on. Since, almost all business information systems are
based on relational databases, it is clear that relational
database schema changes account for a significant share of
the total maintenance cost. This is aggravated by the fact
that a change in database schema has the potential of
driving existing applications out of date. Modifications to
such applications cost a considerable of time and money to
business organisations.
Possible solutions to minimize the costs associated with
this problem are essentially technical in nature. This
dissertation explores a couple of possible solutions in
relational database technology, which could help
organisations to keep their system maintenance cost under
check. The main solutions explored are in the area of data
model patterns and schema evolution. A new branch of schema
evolution called “Non Disruptive Schema Evolution” is
explored as well.
