C170 Exam Questions And Answers!!

Access plan - Answer-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 - Answer-An alternative name for a column or table in a SQL statement. ALTER TABLE - Answer-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 - Answer-In DB2, a named section of permanent storage space that is reserved to store the database. Atomic attribute - Answer-An attribute that cannot be further subdivided to produce meaningful components. For example, a person's last name attribute cannot be meaningfully subdivided. Atomicity - Answer-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 - Answer-A method by which a DBMS finds the most efficient access path for the execution of a query. B-tree index - Answer-An ordered data structure organized as an upside-down tree. Base tables - Answer-Tables on which the view is based batch update routine - Answer-A routine that pools transactions into a single batch to update a master table in a single operation. BETWEEN - Answer-In SQL, a special comparison operator used to check whether a value is within a range of specified y relationship - Answer-An ER term for an association (relationship) between two entities. For example, PROFESSOR teaches CLASS. Bitmap index - Answer-An index that uses a bit array (0s and 1s) to represent the existence of a value or condition. Boolean Algebra - Answer-A branch of mathematics that uses the logical operators OR, AND, and NOT. Boyce-Codd Normal Form (BCNF) - Answer-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 - Answer-A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey. Cardinality - Answer-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 - Answer-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.