SAS P1 L3a Flashcards
What is an SAS library?
SAS library:
- collection of 1 or more files recognized by SAS
- referenced and stored as unit
- highest level of organization of info in SAS
SAS library organization level?
highest level of organization of info in SAS
file relationship to library?
each file is a “member” of a library
Minimum provision of libraries in session of SAS?
at beginning of each session, SAS provides
- at least one temporary library
- at least one permanent library
Give example of temp library
WORK is a temporary library
What happens to data in temporary library during session or at end of session?
Can store and access data sets for duration of session,
but all flushed when session ends
What happens to data in permanent library during session or at end of session?
Can store and access data sets for duration of session,
data sets in permanent library kept after session ends
Give examples of permanent libraries
SASHelp = perm library, has sample data sets to use SASUser = another perm library
What is a libref?
libref = library reference name
What does a libref reference?
libref references particular physical location
recognized by operating system
libref = shortcut to that physical location
how are librefs implemented?
libref implementation corresponds to how operating system stores files.
In Windows, libref usually refers to group of files stored in same folder or directory.
What is the difference between a 1 and 2 level data set name?
- All SAS data sets have a 2 level name, consisting of libref.data-set-name; (separated by period)
- Datasets in temporary work library can have 1 level name (omit “WORK.” )
What if there is only a 1 level name?
SAS assumes it is in the WORK library
=> WORK is the default library
(and is temporary)
What type of name does permanent library need to have?
Permanent library must have 2 level name.
