Difference between in inobs and outobs

[priyankachauhan]

inobs and outobs showing the same no. of rows in the table. so what is the difference between them?

[Shmuel]

in some cases you may want to split observations - e.g write out per date in a range of dates.

in other case you may want to filter your input and select output according to some rules.

in both cases inobs will differ from outobs.

[novinosrin]

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PROC SQL: Beyond the Basics Using SAS®, Second Edition

Kirk Paul Lafler

In Stock

Publisher: SAS Institute

Copyright Date: October 2013

[Reeza]

In the simplest cases they are the same. But as soon as you complicate things they are not. 

They do what it sounds like it does, one controls how many records are read, InOBS) and one controls how many records are output. Since the number of records read obviously affects the outcome they are very different. 
Here's an example of the exact same code and INOBS=2 and OUTOBS=2 in each run. Check the output.

title 'OutObs demo';
proc sql outobs=2;
select age, count(*)
from sashelp.class
group by age
order by age desc;
;
quit;


title 'InObs demo';
proc sql inobs=5;
select age, count(*)
from sashelp.class
group by age
order by age desc;
;
quit;

Results: