a) File Organization: A technique for physically arranging the record of a file on secondary storage devices. b) Sequential File Organization: The storage of records in a file in sequences according to primary key value. c) Indexed File Organization: The storage of records either sequentially or consequentially with an index that allows software to locate individual records. d) Hashed File Organization: A storage system in which the address for each record is determined using a hashing algorithm. e) Denormalization: The process of transforming normalized relations into non-normalized physical record specifications. f) Composite Key: Consists of more than one attribute to uniquely identify an entity occurrence. g) Secondary Key: One field or a combination of fields for which more than one record may have the same combination of values; also called a nonunique key. h) Data Type: A detailed coding scheme recognized by system software, such as DBMS, for representing organizational data. i) Join Index: An index on columns from two or more tables than come from the same domain of values. 2. Match the following terms with the appropriate definitions:
Extent: D. A contagious section of disk space
Hashing Algorithm: F. Converts key value into an address
Index: B. A data structure used to determine in a file the location of a record/records
Physical Record: G. Adjacent fields.
Pointer: E. A field not containing business data.
Data Type: A. A detailed coding scheme for representing organizational data.
Physical File: C. A named area of Secondary memory
3. Contrast the Following Terms
a) Horizontal Partitioning; Vertical Partitioning
Both methods of partitioning involve the creation of additional tables. However, Horizontal Partitioning involves the partitioning of tables to reduce the number of rows, where as vertical partitioning results in more tables with fewer columns.
b) Physical File; Tablespace
A tablespace specifies the storage location of a physical file in a database.
c) Normalization; Denormalization
Normalization results in a database that with pieces of information that are broken into individual, separate tables. A normalized database is created specifically to remove redundant data. However, denormalized databases maintain or add redundant data to speed up read time.
d) Range control; Null control
Range control limits the the allowable values in a field (e.g. number values, number of characters, etc). In contrast, Null control prevents leaving a field empty.
e) Secondary Key; Primary Key
A Primary Key is the main reference key for a given table. A Secondary Key is a candidate key that could also serve as a Primary Key.
4. What are the major inputs into physical database design?
Logical database structures developed during logical design
User processing requirements identified during requirements definition Characteristics for the DBMS and other components of the computer operating environment