Glossary

access mode

the particular database management system (DBMS) that the SQL Query Window is configured to query.

automatic join

a feature of the SQL Query Window that enables you to predefine join criteria for a specific set of tables. When you select these tables for a query in a future session, the join criteria are already defined and are ready for use.

automatic lookup

a feature of the SQL Query Window that automatically displays the values of a particular column when that column is selected in the WHERE EXPRESSION window.

automatic lookup table

a SAS data set that stores information that the SQL Query Window uses to determine how to perform automatic lookup.

calculated column

in a query, a column that does not exist in any of the tables that are being queried, but which is created as a result of a column expression.

catalog

See SAS catalog.

catalog entry

See SAS catalog entry.

column

a vertical component of a table. Each column has a unique name, contains data of a specific type, and has particular attributes. A column is analogous to a variable in SAS terminology.

column alias

a temporary, alternate name for a column. Aliases are optionally specified in the SQL procedure's SELECT clause to name or rename columns. An alias is one word.

column expression

a set of operators and operands that, when evaluated, result in a single data value. The resulting data value can be either a character value or a numeric value.

data set

See SAS data set.

data view

See SAS data view.

format

See SAS format.

group

a set of rows or observations that have the same value or values for one or more common columns or variables.

informat

See SAS informat.

inner join

a join between two tables that returns all of the rows in one table that have one or more matching rows in the other table.

join

the operation that combines data from two or more tables. A join is typically created by means of SQL (Structured Query Language) code or a user interface.

join criteria

the set of parameters that determine how tables are to be joined. Join criteria are usually specified in a WHERE expression or in an SQL ON clause.

library engine

an engine that accesses groups of files and puts them in the correct form for processing by SAS utility windows and procedures. A library engine also determines the fundamental processing characteristics of the library and presents lists of files for the library directory.

library reference

See libref.

libref

a SAS name that is associated with the location of a SAS library. For example, in the name MYLIB.MYFILE, MYLIB is the libref, and MYFILE is a file in the SAS library.

logical operator

an operator that is used in expressions to link sequences of comparisons. The logical operators are AND, OR, and NOT.

lookup table

See automatic lookup table.

missing value

a type of value for a variable that contains no data for a particular row or column. By default, SAS writes a missing numeric value as a single period and a missing character value as a blank space.

null value

a special value that indicates the absence of information. Null values are analogous to SAS missing values.

operand

any of the variables and constants in an expression that contain operators, variables, and constants.

operator

See SAS operator.

outer join

a join between two tables that returns all of the rows in one table, as well as part or all of the rows in the other table. A left or right outer join returns all of the rows in one table (the table on the left or right side of the SQL statement, respectively), as well as the matching rows in the other table. A full outer join returns all of the rows in both of the tables.

profile

a set of parameters that control the behavior of the SQL Query Window.

query

a set of instructions that requests particular information from one or more data sources.

SAS catalog

a SAS file that stores many different kinds of information in smaller units called catalog entries. A single SAS catalog can contain different types of catalog entries.

SAS catalog entry

a separate storage unit within a SAS catalog. Each entry has an entry type that identifies its purpose to SAS.

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 whose contents are 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. Short form: data view.

SAS format

a type of SAS language element that applies a pattern to or executes instructions for a data value to be displayed or written as output. Types of formats correspond to the data's type: numeric, character, date, time, or timestamp. The ability to create user-defined formats is also supported. Examples of SAS formats are BINARY and DATE. Short form: format.

SAS informat

a type of SAS language element that applies a pattern to or executes instructions for a data value to be read as input. Types of informats correspond to the data's type: numeric, character, date, time, or timestamp. The ability to create user-defined informats is also supported. Examples of SAS informats are BINARY and DATE. Short form: informat.

SAS operator

in a SAS expression, any of several symbols that request a comparison, a logical operation, or an arithmetic calculation.

SQL

See Structured Query Language.

Structured Query Language

a standardized, high-level query language that is used in relational database management systems to create and manipulate objects in a database management system. SAS implements SQL through the SQL procedure. Short form: SQL.

summary function

a function that summarizes or describes a group of data values, which are usually numeric data values. For example, SUM and MEAN are summary functions.

summary report

a report that provides a concise overview of information that is derived from one or more data sources. Summary information is typically calculated using descriptive statistics such as SUM, MEAN, and RANGE.

table source

a collection of one or more data sources to be queried.

view

a definition of a virtual data set that is named and stored for later use. A view contains no data; it merely describes or defines data that is stored elsewhere.

WHERE expression

defines the criteria for selecting observations.