SAS/ACCESS 9.2 for Relational Databases: Reference, Fourth Edition

62 How the SAS/ACCESS LIBNAME Statement Works 4 Chapter 7Figure 7.1How SAS Connects to the DBMSSAS/ACCESS softwareEngineInterfaceview enginePass-ThroughFacilityDBMScommunicationmoduleVendorclientlibrariesVendorrelationalDBMSACCESSprocedure*DBLOADprocedure*Client** Client** Server*** The ACCESS procedure and the DBLOAD procedure are not supported by all SAS/ACCESS interfaces.** In some cases, both client and server software can reside on the same machine.You can invoke a SAS/ACCESS relational DBMS interface by using either a LIBNAMEstatement or a PROC SQL statement. (You can also use the ACCESS and DBLOADprocedures with some of the SAS/ACCESS relational interfaces. However, theseprocedures are no longer the recommended way to access relational database data.)How the SAS/ACCESS LIBNAME Statement WorksAccessing Data from a DBMS ObjectYou can use SAS/ACCESS to read, update, insert, and delete data from a DBMSobject as if it were a SAS data set. Here is how to do that:1 You start a SAS/ACCESS interface by specifying a DBMS engine name and theappropriate connection options in a LIBNAME statement.2 You enter SAS requests as you would when accessing a SAS data set.3 SAS/ACCESS generates DBMS-specific SQL statements that are equivalent to theSAS requests that you enter.4 SAS/ACCESS submits the generated SQL to the DBMS.The SAS/ACCESS engine defines which operations are supported on a table and callscode that translates database operations such as open, get, put, or delete intoDBMS-specific SQL syntax. SAS/ACCESS engines use an established set of routineswith calls that are tailored to each DBMS.Processing Queries, Joins, and Data FunctionsTo enhance performance, SAS/ACCESS can also transparently pass queries, joins,and data functions to the DBMS for processing (instead of retrieving the data from the