Glossary

access descriptor

a SAS/ACCESS file that describes data that is managed by SAS, by a database management system, or by a PC-based software application such as Microsoft Excel, Lotus 1-2-3, or dBASE. After creating an access descriptor, you can use it as the basis for creating one or more view descriptors. See also SAS/ACCESS view and view descriptor.

ADABAS descriptor

an ADABAS data field that has been defined as the key data field and which provides an index of the data field's value. The SAS/ACCESS interface to ABABAS supports three descriptor types: subdescriptor, superdescriptor, and phonetic descriptor.

Associator

an ADABAS system file that contains internal storage information that is used for managing the data for an entire database.

batch mode

a method of executing SAS programs in which a file that contains SAS statements plus any necessary operating environment commands is submitted to the computer's batch queue. After you submit the program, control returns to your computer, and you can perform other tasks. Batch mode is sometimes referred to as running in the background. The program output can be written to files or printed on an output device.

browsing data

the process of viewing the contents of a file. Depending on how the file is accessed, you can view SAS data either one observation (row) at a time or as a group in a tabular format. You cannot update data that you are browsing.

ciphered data

data records that are stored in a form that cannot by read by non-ADABAS programs.

compressed data

in ADABAS, data from which blanks in alphanumeric fields and leading zeros in numeric fields have been removed.

data field

the smallest logical unit of information in an ADABAS file. The six types of data fields are elementary, multiple-value, group, periodic group, subfield, and superfield.

Data Storage

an ADABAS file that contains the compressed data records for all ADABAS files. A single physical block of Data Storage contains a varying number of logical records.

data value

a unit of character or numeric information in a SAS data set. A data value represents one variable in an observation. For example, the variable LASTNAME might contain the data value Smith.

database

an organized collection of related data. A database usually contains named files, named objects, or other named entities such as tables, views, and indexes. In ADABAS, a database can consist of up to 5,000 logical files. These files are contained in the Associator system file and in the Data Storage file.

database management system

a software application that enables you to create and manipulate data that is stored in the form of databases. Short form: DBMS.

DBMS

See database management system.

descriptor

See ADABAS descriptor, access descriptor, view descriptor.

descriptor file

a type of SAS/ACCESS file that is used to establish a connection between SAS and files that are created and maintained by other software applications. Descriptor files describe data to SAS. To create descriptor files, you use the ACCESS procedure. There are two types of descriptor files: access descriptors and view descriptors.

editing data

the process of viewing the contents of a file with the intent and the ability to change those contents. Depending on how the file is accessed, you can view the data either one observation at a time or in a tabular format.

elementary field

an ADABAS data field that can contain only one value per record.

engine

a component of SAS software that reads from or writes to a file. Each engine enables SAS to access files that are in a particular file format. There are several types of engines. See also interface view engine.

exclusive file control

the control of one or more files by a single user. Exclusive file control prevents other users from updating the file during a session.

field

See data field.

file

a collection of related records that are treated as a unit. An ADABAS file can contain from 0 to 4,294,967,294 records. The records are physically stored in compressed form in the Data Storage file. File control information, field definitions, and inverted list entries are contained in the Associator system file. SAS files are processed and controlled by SAS and are stored in SAS libraries.

format, SAS variable

a pattern or set of instructions that SAS uses to determine how the values of a variable (or column) should be written or displayed. SAS provides a set of standard formats and also enables you to define your own formats.

group

several consecutive data fields that have been combined into one field so that they can be accessed more efficiently and referred to more easily.

index

(1) in SAS software, a component of a SAS data set that enables SAS to access observations in the SAS data set quickly and efficiently. The purpose of SAS indexes is to optimize WHERE-clause processing and to facilitate BY-group processing. (2) in other software vendors' databases, a named object that directs the DBMS to the storage location of a particular data value for a particular column. Some DBMSs have additional specifications. These indexes also are used to optimize the processing of WHERE clauses and joins. Depending on the SAS interface to a database product and on how selection criteria are specified, SAS might or might not be able to use the DBMS indexes to speed data retrieval.

informat

a pattern or set of instructions that SAS uses to determine how data values in an input file should be interpreted. SAS provides a set of standard informats and also enables you to define your own informats.

interactive line mode

a method of running SAS programs in which you enter one line of a SAS program at a time at the SAS session prompt. SAS processes each line immediately after you press the ENTER or RETURN key. Procedure output and informative messages are returned directly to your display device.

interface view engine

a type of SAS engine that SAS/ACCESS software uses to retrieve data from files that have been formatted by another vendor's software. Each SAS/ACCESS interface has its own interface view engine, which reads the interface product data and returns the data in a form that SAS can understand (that is, in a SAS data set).

Internal Sequence Number

a logical identifier for a recod. Each record in an ADABAS file has a unique ISN. Short form: ISN.

inverted list

a list that contains the different values of a descriptor data field, along with the count and the ISNs of the records that contain each value.

ISN

See Internal Sequence Number.

key

a value that uniquely identifies a specific record in a database.

key field

See ADABAS descriptor.

member

a SAS file in a SAS library.

member name

a name that is assigned to a SAS file in a SAS library.

member type

a SAS name that identifies the type of information that is stored in a SAS file. Member types include ACCESS, AUDIT, DMBD, DATA, CATALOG, FDB, INDEX, ITEMSTOR, MDDB, PROGRAM, UTILITY, and VIEW.

missing value

in SAS, a term that describes the contents of a variable that contains no data for a particular row or observation. By default, SAS prints or displays a missing numeric value as a single period, and it prints or displays a missing character value as a blank space. See also null value.

multiple-value field

an ADABAS data field that can contain 0 to 191 values per record.

null value

in ADABAS, a special value that indicates the absence of information. Null values are analogous to SAS missing values. See also missing value.

observation

a row in a SAS data set. All of the data values in an observation are associated with a single entity such as a customer or a state. Each observation contains either one data value or a missing-value indicator for each variable. An observation is analogous to a row in a database table. However, unlike rows in a database table or file, observations in a SAS data file have an inherent order.

occurrences

the number of values in a single record for an ADABAS multiple-value field, or the number of times a periodic group is repeated in a particular record.

periodic group

a collection of ADABAS data fields that can contain one or more elementary fields and multiple-value fields and which can be repeated up to 191 times.

phonetic descriptor

an ADABAS descriptor that performs a search according to a phonetic value, such as a last name. See also ADABAS descriptor.

SAS data file

a type of SAS data set that contains data values as well as descriptor information that is associated with the data. The descriptor information includes information such as the data types and lengths of the variables, as well as the name of the engine that was used to create the data. See also SAS data set and SAS data view.

SAS data set

a file whose contents are in one of the native SAS file formats. There are two types of SAS data sets: SAS data files and SAS data views. SAS data files contain data values in addition to descriptor information that is associated with the data. SAS data views contain only the descriptor information plus other information that is required for retrieving data values from other SAS data sets or from files that are stored in other software vendors' file formats.

SAS data view

a type of SAS data set that retrieves data values from other files. A SAS data view contains only descriptor information such as the data types and lengths of the variables (columns) plus other information that is required for retrieving data values from other SAS data sets or from files that are stored in other software vendors' file formats. SAS data views can be created by the SAS DATA step and by the SAS SQL procedure.

SAS library

a collection of one or more files that are recognized by SAS and that are referenced and stored as a unit. Each file is a member of the library.

subdescriptor

an ADABAS descriptor that has been derived from part of an elementary data field.

subfield

an ADABAS data field that has been defined from part of another data field. For example, the subfield AREA CODE could be the first three digits of the PHONE data field. Subfields can be used only in read operations.

superdescriptor

an ADABAS descriptor that has been derived from more than one data field, from portions of data fields, or both.

superfield

a data field that consists of several data fields, portions of fields, or both. Superfields can be used only in read operations.

system file

a type of ADABAS file that is used for storing Data Definition Modules (DDMs) and NATURAL SECURITY information. System files are created and maintained by ADABAS and should not be updated directly.

variable

a column in a SAS data set or in a SAS data view. The data values for each variable describe a single characteristic for all observations (rows). Each SAS variable can have the following attributes: name, data type (character or numeric), length, format, informat, and label. In the ACCESS procedure, variables are created from the database product's columns or fields.

variable-length field

an ADABAS data field whose length can vary. The maximum length for a variable-length field is the length that has been specified for its format.

view descriptor

a SAS/ACCESS file that defines part or all of the DBMS data that is described by an access descriptor. This subset consists of selected data fields from an ADABAS file, with optional selection and ordering criteria. See also access descriptor.