In SAS 8 and earlier,
SAS opened a single connection to the DBMS to read a table. SAS statements
requesting data were converted to an SQL statement and passed to the DBMS.
The DBMS processed the SQL statement, produced a result set consisting of
table rows and columns, and transferred the result set back to SAS on the
single connection.
With a threaded read, you can reduce the table read
time by retrieving the result set on multiple connections between SAS and
the DBMS. SAS can create multiple threads, and a read connection is established
between the DBMS and each SAS thread. The result set is partitioned across
the connections, and rows are passed to SAS simultaneously (in parallel) across
the connections, which improves performance.
Copyright © 2010 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
