Accessing a Remote SAS Data Library. Transcript

Transcription

1 Accessing a Remote SAS Data Library Transcript

2 Accessing a Remote SAS Data Library Transcript was developed by Michelle Buchecker. Additional contributions were made by Christine Riddiough and Cheryl Doninger. Editing and production support was provided by the Curriculum Development and Support Department. SAS and all other SAS Institute Inc. product or service names are registered trademarks or trademarks of SAS Institute Inc. in the USA and other countries. indicates USA registration. Other brand and product names are trademarks of their respective companies. Accessing a Remote SAS Data Library Transcript Copyright 2008 SAS Institute Inc. Cary, NC, USA. All rights reserved. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without the prior written permission of the publisher, SAS Institute Inc. Book code E1210, course code RLSPCON3, prepared date 17Jul2008. RLSPCON3_001 ISBN

3 For Your Information iii Table of Contents Lecture Description... iv Prerequisites... v Accessing a Remote SAS Data Library Using Remote Library Services... 4

4 iv For Your Information Lecture Description This is the second e-lecture of a four-lecture series on the basics of SAS/CONNECT software. This lecture teaches you how to use SAS/CONNECT software to access a SAS data library on your remote machine. To learn more For information on other courses in the curriculum, contact the SAS Education Division at , or send to training@sas.com. You can also find this information on the Web at support.sas.com/training/ as well as in the Training Course Catalog. For a list of other SAS books that relate to the topics covered in this Course Notes, USA customers can contact our SAS Publishing Department at or send to sasbook@sas.com. Customers outside the USA, please contact your local SAS office. Also, see the Publications Catalog on the Web at support.sas.com/pubs for a complete list of books and a convenient order form.

5 For Your Information v Prerequisites Before listening to this lecture, you should be able to write DATA and PROC steps understand error messages in the SAS log and debug your program use a LIBNAME statement to access SAS data libraries log on to a remote SAS session through either a SAS spawner or a SAS script file.

6 vi For Your Information Basics of SAS/CONNECT Software Lecture Series Welcome to the lecture series on the basics of SAS/CONNECT software.

7 For Your Information vii Basics of SAS/CONNECT Software Lecture Series Connecting to a Remote Host Accessing a Remote SAS Data Library Distributed Processing Transferring Data and Macro Variables 2 This series consists of four lectures that address connecting to a remote host, accessing a remote SAS data library, distributed processing, and transferring data and macro variables. This is the second lecture in this series, Accessing a Remote SAS Data Library. We encourage you to complete the other three lectures to get a full understanding of the basics of SAS/CONNECT software.

8 viii For Your Information Demonstrations 3 This lecture series includes demonstrations of many lecture tasks. The code used in the demonstrations is available as a handout under the Reference link in the left viewing pane. You can print the handout for your reference at any time.

9 For Your Information ix Exercises 4 The lecture series also includes exercises for you to complete on your own environment. These exercises are optional, but completing them will help you understand the topics presented. When you reach an exercise slide, please pause the recording and minimize this window. A handout with the exercise steps is available under the Reference link. We recommend that you print the exercise handout to have as a reference when completing the exercises. And now, it s time to start lecture 2, Accessing a Remote SAS Data Library. I'll turn things over to your instructor for the series, Michelle.

10 x For Your Information

11 Accessing a Remote SAS Data Library 1. Using Remote Library Services... 4

12 2 Accessing a Remote SAS Data Library

13 1. Using Remote Library Services 3 Accessing a Remote SAS Data Library Welcome to the SAS e-lecture Accessing a Remote SAS Data Library. My name is Michelle and in this lecture we are going to use Remote Library Services to transparently access data on a remote machine.

14 4 Accessing a Remote SAS Data Library 1. Using Remote Library Services Accessing a Remote SAS Data Library 1. Using Remote Library Services 2 So let s go ahead and get started using Remote Library Services.

15 1. Using Remote Library Services 5 Objectives Identify the benefits and considerations of Remote Library Services. Identify the requirements for Remote Library Services. Access a SAS data set on a remote machine using Remote Library Services. 3 We are going to talk about the pros and cons of Remote Library Services, what requirements you need to get it to work, and then actually how to read a remote SAS data set.

16 6 Accessing a Remote SAS Data Library Introduction Remote Library Services (RLS) enable you to define a libref in a local SAS session that points to data residing on a remote machine are implemented through SAS/CONNECT or SAS/SHARE software provide transparent access to remote SAS data sets and external databases such as Oracle and DB2 enable you to read and write to the remote data if you have permission to do so. 4 Remote Library Services, also know as RLS, allows you to write a LIBNAME statement and submit it to your local SAS session, but have the libref point to a SAS data library on a remote machine. This feature is available using either SAS/CONNECT or SAS/SHARE software and has been available since Version 6. With RLS you have access not only to SAS data sets but to any other relational data source that SAS can access, such as DB2 or Oracle. And not only can you read the data, but if you have permissions to do so, you can also write to that data location.

17 1. Using Remote Library Services 7 Remote Library Services Using Remote Library Services, you can execute a SAS program locally to produce a report from remote data. Remote Data 5 Client (Local) Server (Remote) So let s say your data is on a remote machine, and using SAS/CONNECT you have already signed on to that remote machine using a SIGNON statement.

18 8 Accessing a Remote SAS Data Library Remote Library Services Using Remote Library Services, you can execute a SAS program locally to produce a report from remote data. Remote Data 6 Client (Local) Request for Records Server (Remote) Using Remote Library Services you can now point to that data on that remote machine and pretend that it is on your local machine. So any time your step refers to that data, a request is made...

19 1. Using Remote Library Services 9 Remote Library Services Using Remote Library Services, you can execute a SAS program locally to produce a report from remote data. Data Records Remote Data 7 Client (Local) Request for Records Server (Remote) on your behalf to the remote machine and then the records are transferred...

20 10 Accessing a Remote SAS Data Library Remote Library Services Using Remote Library Services, you can execute a SAS program locally to produce a report from remote data. Data Records SAS Program Processing Remote Data 8 Client (Local) Request for Records Server (Remote) across the network to your local machine for processing.

21 1. Using Remote Library Services 11 Benefits of RLS A single copy of the data can be maintained while processing is performed on the local machine. RLS can be used to transfer small to medium sized SAS data sets, which eliminates the need for separate upload and download steps. The data appears to be local. RLS enables updates to remote data as a result of local processing. RLS permits a user interface to reside on the local system while the data is on a remote system. 9 So what are some of the benefits of RLS? First of all, you are only storing one copy of the data. This helps from both a disk storage space issue, as well as preventing obsolete copies of data. Secondly you don t need to upload or download the data, which is useful for small to medium sized data sets. Now the question I normally get asked at this point is "What constitutes small or medium?" and the answer is "It depends." Whatever you think is small or medium, probably is small or medium. I ve even had clients say that they ve been successful with what they considered to be large data sets. Much of it depends on your network speed and available bandwidth, more than anything else. Another benefit is that the data appears to be local, so you can view it using your SAS Explorer window. Also if you have permissions to update the data, you can do so even though the processing is occuring on the local machine. And lastly, if you have a custom front-end interface, it can run on one machine even though the data physically resides on a different machine.

22 12 Accessing a Remote SAS Data Library Considerations of RLS Multiple passes of the data requires the same data to go across the network multiple times. Examples include statistical procedures multiple PROC steps on the same data. Network traffic might significantly increase. 10 So what are the downsides of RLS? Well, some procedures, like the statistical procedures, require multiple passes through the same data set. This means that the same data is being pulled across the network multiple times. Likewise if you are running more than one step against the same SAS data set, each time that the step runs it will request the data from the remote machine. You might also see an increase in network traffic because of this. So while RLS is great in some instances, it is not a good option in all instances.

23 1. Using Remote Library Services 13 Requirements for RLS To use RLS, you need SAS/CONNECT on both machines to sign on to the remote machine to begin a remote SAS session to issue a LIBNAME statement in your local session with the SERVER= option. 11 To use Remote Library Services, you need to have SAS/CONNECT on both machines, you must be signed on to the remote machine through either a script file or spawner, and then you need to submit a LIBNAME statement to your local SAS session that has the SERVER= option.

24 14 Accessing a Remote SAS Data Library SERVER= Option General form of the SERVER= option in the LIBNAME statement: LIBNAME libref 'SAS-data-library' SLIBREF=server-libref SERVER=remote-host; libref SAS-datalibrary server-libref remote-host is a libref defined to your local session referencing a remote SAS library. is the physical location of the remote SAS library. is an existing libref in the server s session, for example, work. is the same name previously specified with OPTIONS REMOTE=ID value. 12 The syntax of the LIBNAME statement is the keyword LIBNAME followed by your library reference. Next, in quotation marks is the name of the SAS data library location as it is called on your remote machine. Let s ignore the SLIBREF= option for the moment. Then you use the SERVER= option and specify the name of your remote machine that you are connected to.

25 1. Using Remote Library Services 15 SERVER= Option Examples: Access a library stored on your user ID on z/os: libname rmtmvs '.orion.sasdata' server=sdcmvs; Access a library stored on your user ID on UNIX: libname rmtunix '~/orion/sasdata' server=bcom1; Access the work library on z/os: libname rmtwork slibref=work server=sdcmvs; 13 So let s take a look at a few examples. In this first example, let s say I have already signed on to an MVS machine named sdcmvs. In my LIBNAME statement, I d type libname rmtmvs (or any other library reference name) and then in quotation marks dot orion dot sasdata, followed by server=sdcmvs, semicolon. By starting the filename with a dot, SAS will automatically append my MVS user ID to the front of the location. For the second example, let s that say I am connected to a UNIX machine named bcom1. Then my LIBNAME statement would be libname, my library reference, (and here I m just making up a name) rmtunix, then in quotation marks the directory on my UNIX operating system for my SAS data library, such as tilde, slash, orion, slash, sasdata, and lastly server=bcom1, semicolon. Now let s say that you already have a SAS data library in your remote SAS session that you want to access. For instance, when I sign on to my remote SAS session, I will automatically get a work library in that remote session. If you want to access that library, then you would use the SLIBREF= option instead of a physical location. So in the last example I ll write libname rmtwork slibref=work server=sdcmvs;, and this creates a local libref called rmtwork, which points to the work library on the remote machine. Very important! This LIBNAME statement is submitted to your local SAS session.

26 16 Accessing a Remote SAS Data Library If accessing a relational DBMS using the SAS/ACCESS LIBNAME Engine, you must use the RENGINE and ROPTIONS options. libname rlsdb2 rengine=db2 server=sdcmvs roptions="ssid=db2 authid=educ";

27 1. Using Remote Library Services 17 Submitting Statements After the libref on the local machine is established, any code submitted that references that library will access the remote data and be processed on the local machine. 14 After you have submitted your LIBNAME statement, then you can pretend that the data is stored locally. Any code submitted that references that data will be processed on the local machine.

28 18 Accessing a Remote SAS Data Library Using Remote Library Services This demonstration illustrates using Remote Library Services to connect to a remote SAS data library and produce a listing report. 15 Let s take a look at an example program to sign on to a UNIX machine and use Remote Library Services and produce a listing report. Please refer to your handout to see the code being submitted. In this program I am creating a macro variable named MYUNIX whose value is the name of my UNIX machine. Then I have an OPTIONS statement setting the COMAMID and the REMOTE= option to MYUNIX, followed by the FILENAME statement for the script and a SIGNON statement. Next is my LIBNAME statement of libname orion, quote, the name of the SAS data library on my remote UNIX machine, close quote, and server= the name of my UNIX machine. Notice that this LIBNAME statement is not inside of an RSUBMIT block, which means it will be submitted to my local windows SAS session. Next I have a PROC PRINT step listing ORION.STAFF as the name of the SAS data set to print, a WHERE statement to subset the data, and a VAR statement and a run. Let me go ahead and submit this program. I ll be prompted to sign on, so I ll type in my user ID. And password. And we see a listing of the data of salaries greater than $50,000.

29 1. Using Remote Library Services 19 Let me go to the SAS Explorer window. Notice the Orion icon looks different than the other librefs. That is because it is an RLS library. If I right-click on the Orion libref and select Properties, you ll notice that it has the UNIX path file and the engine of remote. I m going to close this window and double-click on the Orion libref. And here is a list of all the SAS data sets that exist on that remote machine in that location. So this is the beauty of RLS. Once you submit the LIBNAME statement with the SERVER= option, the data really does appear as if it resides on your local machine even though it doesn t.

30 20 Accessing a Remote SAS Data Library Processing WHERE Criteria The previous demonstration included a WHERE statement in PROC PRINT. Which machine processed the WHERE criteria, the local or remote machine? 16 In the demonstration you might have noticed a WHERE statement in the PROC PRINT. From our earlier discussion, you know that PROC PRINT is processed on the local machine chance, which machine do you think processes the WHERE statement, local or remote?

31 1. Using Remote Library Services 21 Processing WHERE Criteria The previous demonstration included a WHERE statement in PROC PRINT. Which machine processed the WHERE criteria, the local or remote machine? Remote The exception would be if there were a function or format that is not found on the remote machine. Then the WHERE criteria is processed by the local machine. 17 Surprisingly it is the remote machine. SAS is smart enough to know that if there is a WHERE statement that subsets the data, it is best to only return the data that meets that criteria. This sends less data over the network, and so speeds up the overall elapsed time. The exception to this rule is if there is a function or format being used in the WHERE statement (or WHERE clause in PROC SQL) that only exists on the local machine and not the remote machine. The PROC PRINT code is still processed by the local machine.

32 22 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff; by salary; run; Which machine performs the sort, local or remote? What is the name of the sorted data set? Which machine is it stored on, local or remote? 18 Now, let s take a look at this PROC SORT step. It s proc sort data=orion.staff; by salary; run; where the libref of orion was assigned using Remote Library Services. Which machine do you think performs the sort, local or remote? What is the name of the sorted data set? Which machine is it stored on, local or remote? You can pause the recording while you contemplate your answers.

33 1. Using Remote Library Services 23 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? Which machine is it stored on, local or remote? 19 As with the PROC PRINT in the demonstration, the PROC SORT processing occurs on the local machine.

34 24 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? orion.staff Which machine is it stored on, local or remote? 20 Because there is no OUT= option, the name of the sorted data set is the same as the incoming data set, orion.staff.

35 1. Using Remote Library Services 25 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? orion.staff Which machine is it stored on, local or remote? 21 Remote And because orion is an RLS libref, it is on the remote machine. So think about what just happened here. SAS transferred the data from the remote machine to the local, sorted it on the local, and pushed it back to the remote. Is this technique something that you would consider doing? Well, it s possible that the CPU of the remote machine is so overloaded that it wouldn t be able to process the PROC SORT step in a timely manner. So in this case we were able to offload work from a busy machine.

36 26 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=work.staff; by salary; run; Which machine performs the sort, local or remote? What is the name of the sorted data set? Which machine is it stored on, local or remote? 22 Now let s add an OUT= option that has out=work.staff. How does that change things? So which machine performs the sort? What is the name of the sorted data set Which machine is it stored on, local or remote? Again, feel free to pause the recording while you answer these questions.

37 1. Using Remote Library Services 27 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=work.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? Which machine is it stored on, local or remote? 23 So just like before, the processing is done on the local machine.

38 28 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=work.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? work.staff Which machine is it stored on, local or remote? 24 Because we used an OUT= option, the name of the sorted data set is work.staff.

39 1. Using Remote Library Services 29 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=work.staff; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? work.staff Which machine is it stored on, local or remote? Local 25 And because work is a libref that is on our local machine, this sorted data set is stored locally.

40 30 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=orion.sorted; by salary; run; Which machine performs the sort, local or remote? What is the name of the sorted data set? Which machine is it stored on, local or remote? 26 OK, last example. In this case, we are still using an OUT= option, but this time it has out=orion.sorted. So what are the answers to the questions now? Please pause the recording while you answer.

41 1. Using Remote Library Services 31 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=orion.sorted; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? Which machine is it stored on, local or remote? 27 As before, the sort occurs on the local machine.

42 32 Accessing a Remote SAS Data Library Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=orion.sorted; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? orion.sorted Which machine is it stored on, local or remote? 28 The name of the sorted data set is orion.sorted.

43 1. Using Remote Library Services 33 Sorting Data Examine the PROC SORT clause shown below: proc sort data=orion.staff out=orion.sorted; by salary; run; Which machine performs the sort, local or remote? Local What is the name of the sorted data set? orion.sorted Which machine is it stored on, local or remote? Remote 29 And because the libref is orion, and the orion libref points to a SAS data library on the remote machine, the output data set is stored on the remote machine. So how did you do on these questions? Do you have a good understanding now of how Remote Library Services works?

44 34 Accessing a Remote SAS Data Library Exercise Remote Library Services Find a SAS data library that you can access on your remote machine. Using your script file or spawner, connect to your remote machine and issue a LIBNAME statement with the SERVER= option to point to that remote library. Submit a PROC CONTENTS step against a SAS data set in that remote library. 30 For this exercise, follow the instructions on the slide to use Remote Library Services in your environment.

45 1. Using Remote Library Services 35 Credits Accessing a Remote SAS Data Library was developed by M. Michelle Buchecker. Additional contributions were made by Chris Riddiough and Cheryl Doninger. 31 This concludes the SAS e-lecture Accessing a Remote SAS Data Library. I hope you have found the material in this lecture to be helpful to your work tasks.

46 36 Accessing a Remote SAS Data Library Comments? We would like to hear what you think. Do you have any comments about this lecture? Did you find the information in this lecture useful? What other e-lectures would you like to see SAS develop in the future? Please your comments to EDULectures@sas.com 32 If you have any comments about this lecture or e-lectures in general, we would appreciate receiving your input. You can use the address listed here to provide that feedback.

47 1. Using Remote Library Services 37 Copyright SAS and all other SAS Institute Inc. product or service names are registered trademarks or trademarks of SAS Institute Inc. in the USA and other countries. indicates USA registration. Other brand and product names are trademarks of their respective companies. Copyright 2008 by SAS Institute Inc., Cary, NC 27513, USA. All rights reserved. 33 Thank you for your time.

48 38 Accessing a Remote SAS Data Library