ascending order
describes records placed in order from lowest to highest based on the value in a field
backup file
a copy that is kept in case values need to be restored to their original state
batch processing
involves performing the same tasks with many records, one after the other
binary files
contain data that has not been encoded as text
byte
a small unit of storage; for example, in a simple text file, a byte holds only one character
characters
are letters, numbers, and special symbols, such as A, 7, and $
child file
a copy of a file after revision
closing a file
makes a file no longer available to an application
computer file
a collection of data stored on a nonvolatile device in a computer system
control break
a temporary detour in the logic of a program
control break field
holds a value that causes special processing in a control break program
control break program
a program in which a change in the value of a variable initiates special actions or causes special or unusual processing to occur
control break report
is a form of output that includes special processing after each group of records
data hierarchy
is a framework that describes the relationships between data components; contains characters, fields, records, and files
database
holds groups of files and provides methods for easy retrieval and organization
default input and output devices
are devices that do not require opening; usually they are the keyboard and monitor, respectively
descending order
describes records placed in order from highest to lowest based on the value in some field
direct access files
are random access files
directories
are organization units on storage devices; each can contain multiple files as well as additional directories; in a graphic system, often called folders
fields
are data items that represent a single attribute of a record and are composed of one or more characters
files
are groups of related records
folders
are organization units on storage devices; each can contain multiple files as well as additional folders; are graphic directories
gigabyte
is a billion bytes
instant access files
are random access files in which records must be accessed immediately
interactive program
program where the user makes direct requests, as opposed to one in which input comes from a file
kilobyte
is approximately 1000 bytes
master file
holds complete and relatively permanent data
megabyte
is a million bytes
merging files
involves combining two or more files while maintaining the sequential order
opening a file
locates the file on a storage device and associates a variable name within your program with the file
parent file
a copy of a file before revision
path
is the combination of a file's disk drive and the complete hierarchy of directories in which the file resides
permanent storage devices
hold nonvolatile data; examples include hard disks, DVDs, USB drives, and reels of magnetic tape
random access files
records can be located in any order
reading from a file
copies data from a file on a storage device into RAM
real-time applications
require that a record be accessed immediately while a client or user is waiting
records
are groups of fields that go together for some logical reason
sequential file
a file in which records are stored one after another in some order
single-level control break
is a break in the logic of a program to perform special processing based on the value of a single variable
sorting
the process of placing records in order by the value in a specific field or fields
tables
are files in a database
text files
contain data that can be read in a text editor
transaction file
holds temporary data that you use to update a master file
update a master file
involves making changes to the values in its fields based on transactions
writing to a file
copies data from RAM to persistent storage