C170 QUESTION AND ANSWER
ALREADY PASSED
Access plan -✔✔A set of instructions generated at application compilation time that is created and
managed by a DBMS. The access plan predetermines how an application's query will access the
database at run time.
Alias -✔✔An alternative name for a column or table in a SQL statement.
ALTER TABLE -✔✔The SQL command used to make changes to table structure. When the command is
followed by a keyword (ADD or MODIFY), it adds a column or changes column characteristics.
AREA -✔✔In DB2, a named section of permanent storage space that is reserved to store the
database.
Atomic attribute -✔✔An attribute that cannot be further subdivided to produce meaningful
components. For example, a person's last name attribute cannot be meaningfully subdivided.
Atomicity -✔✔The transaction property that requires all parts of a transaction to be treated as a
single, indivisible, logical unit of work. All parts of a transaction must be completed or the entire
transaction is aborted.
automatic query optimization -✔✔A method by which a DBMS finds the most efficient access path
for the execution of a query.
B-tree index -✔✔An ordered data structure organized as an upside-down tree.
Base tables -✔✔Tables on which the view is based
batch update routine -✔✔A routine that pools transactions into a single batch to update a master
table in a single operation.
, BETWEEN -✔✔In SQL, a special comparison operator used to check whether a value is within a range
of specified values.
binary relationship -✔✔An ER term for an association (relationship) between two entities. For
example, PROFESSOR teaches CLASS.
Bitmap index -✔✔An index that uses a bit array (0s and 1s) to represent the existence of a value or
condition.
Boolean Algebra -✔✔A branch of mathematics that uses the logical operators OR, AND, and NOT.
Boyce-Codd Normal Form (BCNF) -✔✔A special type of third normal form (3NF) in which every
determinant is a candidate key. A table in BCNF must be in 3NF. See also determinant.
Candidate Key -✔✔A minimal superkey; that is, a key that does not contain a subset of attributes
that is itself a superkey.
Cardinality -✔✔A property that assigns a specific value to connectivity and expresses the range of
allowed entity occurrences associated with a single occurrence of the related entity.
Cascading order sequence -✔✔A nested ordering sequence for a set of rows, such as a list in which
all last names are alphabetically ordered and, within the last names, all first names are ordered.
Closure -✔✔A property of relational operators that permits the use of relational algebra operators
on existing tables (relations) to produce new relations.
Composite Attribute -✔✔An attribute that can be further subdivided to yield additional attributes.
For example, a phone number such as 615-898-2368 may be divided into an area code (615), an
exchange number (898), and a four-digit code (2368). Compare to simple attribute.
Composite Entity -✔✔An entity designed to transform an M:N relationship into two 1:M
relationships. The composite entity's primary key comprises at least the primary keys of the entities
that it connects. Also known as a bridge entity. See also linking table.
ALREADY PASSED
Access plan -✔✔A set of instructions generated at application compilation time that is created and
managed by a DBMS. The access plan predetermines how an application's query will access the
database at run time.
Alias -✔✔An alternative name for a column or table in a SQL statement.
ALTER TABLE -✔✔The SQL command used to make changes to table structure. When the command is
followed by a keyword (ADD or MODIFY), it adds a column or changes column characteristics.
AREA -✔✔In DB2, a named section of permanent storage space that is reserved to store the
database.
Atomic attribute -✔✔An attribute that cannot be further subdivided to produce meaningful
components. For example, a person's last name attribute cannot be meaningfully subdivided.
Atomicity -✔✔The transaction property that requires all parts of a transaction to be treated as a
single, indivisible, logical unit of work. All parts of a transaction must be completed or the entire
transaction is aborted.
automatic query optimization -✔✔A method by which a DBMS finds the most efficient access path
for the execution of a query.
B-tree index -✔✔An ordered data structure organized as an upside-down tree.
Base tables -✔✔Tables on which the view is based
batch update routine -✔✔A routine that pools transactions into a single batch to update a master
table in a single operation.
, BETWEEN -✔✔In SQL, a special comparison operator used to check whether a value is within a range
of specified values.
binary relationship -✔✔An ER term for an association (relationship) between two entities. For
example, PROFESSOR teaches CLASS.
Bitmap index -✔✔An index that uses a bit array (0s and 1s) to represent the existence of a value or
condition.
Boolean Algebra -✔✔A branch of mathematics that uses the logical operators OR, AND, and NOT.
Boyce-Codd Normal Form (BCNF) -✔✔A special type of third normal form (3NF) in which every
determinant is a candidate key. A table in BCNF must be in 3NF. See also determinant.
Candidate Key -✔✔A minimal superkey; that is, a key that does not contain a subset of attributes
that is itself a superkey.
Cardinality -✔✔A property that assigns a specific value to connectivity and expresses the range of
allowed entity occurrences associated with a single occurrence of the related entity.
Cascading order sequence -✔✔A nested ordering sequence for a set of rows, such as a list in which
all last names are alphabetically ordered and, within the last names, all first names are ordered.
Closure -✔✔A property of relational operators that permits the use of relational algebra operators
on existing tables (relations) to produce new relations.
Composite Attribute -✔✔An attribute that can be further subdivided to yield additional attributes.
For example, a phone number such as 615-898-2368 may be divided into an area code (615), an
exchange number (898), and a four-digit code (2368). Compare to simple attribute.
Composite Entity -✔✔An entity designed to transform an M:N relationship into two 1:M
relationships. The composite entity's primary key comprises at least the primary keys of the entities
that it connects. Also known as a bridge entity. See also linking table.
