Glossary - Database Design and Development: An Essential Guide for IT Professionals - page 713

Logical design. Process of designing and creating a logical data model.
Model transformation. Process of mapping and transforming the components of a
semantic data model to those of a logical or conventional data model.
Network data model. A data model where the data structures are arranged in a
network of nodes.
Nonprocedural language. Language used for stating what result is required from a
database transaction rather than stipulating the procedure on how to obtain the
result.
Normal form. A state of a relation free from incorrect dependencies among the
attributes. See Boyce-Codd normal form , First normal form , Second normal form ,
and Third normal form .
Normalization. The step-by-step method of transforming a random relation into a
set of normalized relations free from incorrect dependencies and conforming to
the rules of the relational data model.
Null value. A value of an attribute, different from zero or blank to indicate a
missing, nonapplicable or unknown value.
Object. A physical or conceptual “thing” of interest to an organization, data about
which is stored in the database.
Object-based data modeling. Data modeling method that combines the techniques
of data modeling and object technology to create a semantic data model to rep-
resent the information requirements of an organization.
Object instance. A single occurrence in an object set.
Object set. Set of object instances of the same type. The CUSTOMER object set
includes all customers.
ODBC (Open Database Connectivity). A programming interface from Microsoft
that provides a common language interface for Windows applications to access
databases on a network.
Object-relational data model. Combines the capabilities of object technology to
handle complex data types and advanced relationship types with features of data
integrity, reliability, and recovery found in the relational realm.
OLAP (online analytical processing). Powerful software systems providing exten-
sive multidimensional analysis, complex calculations, and fast response times.
Usually present in data warehousing systems.
Partitioning. See Data fragmentation .
Performance tuning. Actions usually taken by the DBA to improve the perfor-
mance of the database on an ongoing basis.
Physical data model. Data model, consisting of the actual components such as data
files, blocks, records, storage allocations, indexes, and so on, representing the
information requirements of an organization at a physical level of hardware and
system software.
Physical design. Process of designing the physical data model.
Physical object set. Set representing the physical objects themselves, not the types
of objects.
Pointer. A logical or physical address of a data element in the database, usually
embedded within a data record.