Modern Database Management Chapter 5 (12th edition)
Extent
A contiguous section of disk storage space.
Data Type
A detailed coding scheme recognized by system software, such as a DBMS, for representing organizational data.
Pointer
A field of data indicating a target address that can be used to locate a related field or record of data.
Hash index table
A file organization that uses hashing to map a key into a location in an index, where there is a pointer to the actual data record matching the hash key
Tablespace
A named logical storage unit in which data from one or more dataspace tables, views, or other database objects may be stored.
Physical file
A named portion of secondary memory (such as a hard disk) allocated for the purpose of storing physical records.
Hashing algorithm
A routine that converts a primary key value into a relative record number or relative file address
Hashed file organization
A storage system in which the address for each record is determined using a hashing algorithm
Index
A table of other data structure used to determine in a file the location of records that satisfy some condition.
File organization
A technique for physically arranging the records of a file on secondary storage devices.
Join Index
An index on columns from two or more tables that come from the same domain of values
Vertical partitioning
Distribution of the columns of a logical relation into several separate physical tables.
Horizontal Partitioning
Distribution of the rows of logical relation into several seperate tables
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 non-unique key.
Denormalization
The process of transforming normalized relations into non-normalized physical record specifications.
Field
The smallest unit of application data recognized by system software
Indexed file organization
The storage of records either sequentially or non sequentially with an index that allows software to locate individual records
Sequential file organization
The storage of records in a file in sequence according to a primary key value.
