Listing Integrity Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631
Rejected Observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631
Integrity Constraints and CEDA Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 632
Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 632
Understanding SAS Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 638
Definition of SAS Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 638
Benefits of an Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639
The Index File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639
Types of Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640
Deciding Whether to Create an Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642
Guidelines for Creating Indexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644
Creating an Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646
Using an Index for WHERE Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 648
Using an Index for BY Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654
Using an Index for Both WHERE and BY Processing . . . . . . . . . . . . . . . . . . . . . . 655
Specifying an Index with the KEY= Option for SET and MODIFY Statements . . 656
Taking Advantage of an Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 656
Procedures and SAS Operations That Maintain Indexes . . . . . . . . . . . . . . . . . . . . 656
Extended Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660
Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660
Enabling and Manipulating Extended Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . 660
Compressing Data Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661
Definition of Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661
Requesting Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 661
Disabling a Compression Request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662
Extending the Observation Count for a 32-Bit SAS Data File . . . . . . . . . . . . . . . . 662
Definition of Extended Observation Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662
Understanding the Extended Observation Count . . . . . . . . . . . . . . . . . . . . . . . . . . 662
Using the EXTENDOBSCOUNTER= Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663
Recovering from an Exceeded Maximum Observation Count . . . . . . . . . . . . . . . . 664
Extended Observation Count File Attribute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664
Extended Observation Count Behavior Considerations . . . . . . . . . . . . . . . . . . . . . 665
Extending the Observation Count in a 64-Bit Operating Environment . . . . . . . . . 665
When Extending the Observation Count Is Supported . . . . . . . . . . . . . . . . . . . . . . 666
Definition of a SAS Data File
A SAS data file is a type of SAS data set that contains both the data values and the
descriptor information. SAS data files have the member type of DATA. There are two
general types of SAS data files:
native SAS data file
stores the data values and descriptor information in a file that is formatted by SAS.
interface SAS data file
stores the data in a file that was formatted by software other than SAS. SAS provides
engines for reading and writing data from files that were formatted by software such
as ORACLE, DB2, Sybase, ODBC, BMDP, SPSS, and OSIRIS. These files are
interface SAS data files, and when their data values are accessed through an engine,
SAS recognizes them as SAS data sets.
Note: The availability of engines that can access different types of interface data
files is determined by your site licensing agreement. See your system
606 Chapter 26 SAS Data Files
..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset
3.21.46.92