Attribute An attribute
is a characteristic or property of an ENTITY. In relational database
terminology an attribute usually means a column or FIELD in a table
AutoNumber The AutoNumber data type
stores an integer that Access increments (adds to) automatically
as you add new records. You can use the AutoNumber data type as
a unique record identification for tables having no other unique
value.
Boyce-Codd normal form A table
is in third normal form (3NF) and all determinants are candidate
keys
Business Rule A business operation reflected
in the design of a database
Candidate Key A field or fields
that qualifies as a Primary Key
Cyclic Dependency Occurs when
there is a multi-field primary key with three or more fields (for
example, fields A, B, C) and those fields are related in pairs of
A and B, B and C, and A and C
Database A group
of tables holding related information
Deletion Anomaly Inability to delete unwanted
data without deleting data that you need to retain
Denormalise To intentionally
create tables with data that is not normalised, usually done for
performance purposes
Determinant A field in which the value determines
the value in another field
Entity An entity is a single object about which
data can be stored. It is the "subject" of a table. Entities
and their interrelationships are modeled through the use of entity-relationship
diagrams
ER Diagram A graphical representation of the
tables (entities) in a database and the relationships between them
Fifth Normal Form A table
is in fourth normal form (4NF) and there are no cyclic dependencies
First Normal Form A table in in
first normal form (1NF) if there are no repeating groups
Foreign Key The Primary
Key from one table is added to another table so the records can
be related
Fourth Normal Form A table
is in Boyce-Codd normal form (BCNF) and there are no multi-valued
dependencies
Functional Dependency A relationship between
fields such that the value in one field determines the one value
that can be contained in the other field
Inner Join A join of two tables
that returns records for which there is a matching value in the
field on which the tables are joined
Insertion Anomaly Inability to add new records
or values without creating data problems such as blank values
Intersection Table A table added to the database
to break down a many-to-many relationship to form two one-to-many
relationships
Many-To-Many Relationship A relationship
between two tables in which many records in one table can be related
to many records in the other table
Modification Anomaly Inability to accurately
and efficiently maintain data
Multi-field Primary Key A combination
of two or more fields that uniquely identifies an individual record
Multi-valued dependency (MVD) Occurs when, for
each value in field A, there is a set of values for field B and
a set of values for field C but fields B and C are not related
Natural Join An inner join in which redundant
columns are eliminated
Non-key Field A field that is not part of a foreign
or primary key
Normal Forms Standards for the design of tables
in a relational database
Normalisation
The process of decomposing large tables into smaller ones in order
to eliminate redundant data and duplicate data.
One-To-Many Relationship
A relationship between two tables in which one record in one table
potentially can be related to many records in another table
One-To-One Relationship
A relationship between two tables in which each record in one table
relates to a maximum of one record in the other table
Orphan Record A record in a related or child
table with no matching record in the primary or parent table
Outer Join A join between two tables
that returns all the records from one table and, from the second
table, only those records in which there is a matching value in
the field on which the tables are joined
Primary Key A field or fields
that hold values that are unique to each record
Primary Table The table on the one side of a
one-to-many relationship
Record A row of data about a single item
Related Table The table on the many side of a
one-to-many relationship
Relational Database Data stored in a structure
of rows and columns
Relational Database Management System (RDBMS)
A software application that utilizes a relational database model
to hold the data used in the application
Repeating Group A set of logically related fields
or values that occur multiple times in one record
Second Normal Form A table is in
first normal form (1NF) and each non-key field is functionally dependent
on the entire primary key
Self Join The Self-Join is
a join that relates data in a table to itself. A table is joined
to itself based upon a field or combination of fields that have
duplicate data in different records. The data-type
of the inter-related columns must be of the same type.
SQL Structured
Query Language (SQL) is both the International Organization for
Standardization (ISO) and the American National Standards Institute
(ANSI) standard language for creating, updating and querying relational
database management systems (RDBMS).
Table Rows and columns
of data about a single subject
Third Normal Form A table is in
second normal form (2NF) and there are no transitive dependencies
Transitive Dependency A type of functional dependency
in which the value in a non-key field is determined by the value
in another non-key field and that field is not a candidate key