topic Re: IORC process in Data Step by using Index. in SAS Programming

IORC process in Data Step by using Index.

Ajayvit — Thu, 27 Jul 2023 08:09:40 GMT

Hi Team,

I want to understand about IORC process in Data Step by using Index.

My requirement is we have two data set (A and B),(A) is small and (B)is very large.

I do understand that for large data set we can create index. But how to merge tow data set using __IORC__ technique. ?

*Index larger file;
proc datasets lib=work;
modify daset_name;
index create variable_name/unique;
quit;

Re: IORC process in Data Step by using Index.

JosvanderVelden — Thu, 27 Jul 2023 08:36:26 GMT

Have a look at this paper: https://www.lexjansen.com/wuss/2003/SASSolutions/c-an_animated_guide_speed_merges__iorc_.pdf

Re: IORC process in Data Step by using Index.

Ajayvit — Thu, 27 Jul 2023 08:39:11 GMT

Hi Josvander,

Thank you for your help.

I have been there i was not able to understood the solution thats why i am here.

Thank You.

Re: IORC process in Data Step by using Index.

JosvanderVelden — Thu, 27 Jul 2023 08:57:55 GMT

Does example 4 from the documentation help in understanding?
https://documentation.sas.com/doc/en/lrcon/9.4/n1tgk0uanvisvon1r26lc036k0w7.htm#n1g54zcicf3fu4n16aopbargavvz
If not do you understand the fundamentals of datastep programming with regards to the PDV? There is a great youtube video on that: https://youtu.be/7EMOai04_eg.

Re: IORC process in Data Step by using Index.

Kurt_Bremser — Thu, 27 Jul 2023 09:08:25 GMT

The paper is very nicely done and describes every single step of the process in depth. I could not think of a better way to describe how the statements work.

What in particular do you not understand?

Keep in mind that this is advanced technique, so a certain level of SAS knowledge is required to understand it, combined with the skillset of a programmer.

My personal preference for lookups into a small table while processing a large one is the hash object.

Re: IORC process in Data Step by using Index.

Ajayvit — Fri, 28 Jul 2023 03:04:39 GMT

What i did not understood is :

here we are performing lookup for common variable and value which is like (if a and b in merge) but how to manipulate this condition like if a or if a and not b like this.

Thank you.

Re: IORC process in Data Step by using Index.

Kurt_Bremser — Fri, 28 Jul 2023 06:04:27 GMT

After the execution of the second SET statement, the _IORC_ variable will tell you if the statement succeeded (0) or not (1).

The section "Selecting Observations in Both Files" shows an example for "if a and b". By checking for 0 (instead of NE 0), you get the code for "a and not b".