Messages in the log.

[deleted_user]

Two tables:

A with variables ID, X, Y.
B with variables ID, Z

Merging:

data C;
merge A B;
by ID;
run;

If anyone of A and B is not sorted by ID, shouldn't there be a message in the log about it?

[Flip]

Only if they are not in the correct order. The message is generated when data lines are encountered in the wrong order, not due to a sort indicator.

[deleted_user]

Thanks for your answer.

In my example above table A was sorted by ID with PROC SORT, but table B was not.

So, since there was no message concerning table B, I can draw the conclusion, for sure, that the records in B was in correct order?

You NEVER have to worry when there is a BY in the merging, that you get something that you don't want?

[sbb]

As long as you do not code the BY statement parameter NOSORTED. Useful reading below, for your consideration.

Scott Barry
SBBWorks, Inc.

SAS Language Reference: Concepts, Processing BY-Groups in the DATA Step
http://support.sas.com/documentation/cdl/en/lrcon/61722/HTML/default/a000761932.htm

[data_null__]

MERGE does not support BY statement with NOTSORTED option.