While working with cas tables with sort alike operations, when Do I really need single=yes option?

[acordes]

I wonder in which cases related to first, last, lag, dif... operations I do need to run the data step in single mode to get the right results.

Whether I comment or not the single thread option the resulting table is correct.

Does it depend on the size of the table if cas runs in multimode?

data CASUSER.TESTA_DUP2;
/*  / SESSREF='mysession' single=yes; */
   set PUBLIC.WET_PX10_MAN_NOM_SL;
by timestamp sample_id;
if first.timestamp then _position_ = 0;
_position_+1;
run;

proc cas;
source MPG_toyota;
		create table CASUSER.TESTA_DUP2{options replace=true} as 
			select a.*, _frequency_
               from CASUSER.TESTA_DUP2 a left join 
				(select timestamp, max(_position_) as _frequency_ from CASUSER.TESTA_DUP2 group by 1)  b 
			on a.timestamp=b.timestamp  ;
endsource;
fedSQL.execDirect / query=MPG_toyota;
quit;

[sbxkoenk · Accepted solution]

Hello ,

use this option 

options MSGLEVEL=I ;

to get full info in the LOG.

The ADDROWID data set option maintains the order of your data when executing a DATA step in SAS® Cloud Analytic Services (CAS)

By Kevin Russell on SAS Users August 17, 2022
Topics | Programming Tips
https://blogs.sas.com/content/sgf/2022/08/17/the-addrowid-data-set-option-maintains-the-order-of-you...

The ADDROWID option is not existing in SAS Viya 3.5. You need SAS Viya 4 for that one.

For completeness , I add this link :

SAS Help Center: SAS CALL Routines and Functions That Are Not Supported in CAS

Ciao,

Koen