DATA Step, Macro, Functions and more

Interleaving question Sort indicator

Accepted Solution Solved
Reply
N/A
Posts: 1
Accepted Solution

Interleaving question Sort indicator

I have two sorted SAS data sets and now want to interleave them together.  I am noticing after interleaving them using the same by variable that both are sorted on, the sort indicator is not retained in the resulting dataset.  Does anyone know why after interleaving these datasets the sort indicator (I'm validating using proc contents) would no longer be set ?


Accepted Solutions
Solution
‎04-07-2015 11:45 AM
Super User
Posts: 5,498

Re: Interleaving question Sort indicator

The DATA step has the potential to destroy the sorted order.  For example, this would be a legal program:

data new;

   set already_sorted;

   by id;

   if amount > 1000 then id='ABC';

run;

The new data set is not sorted, even though the incoming data set is sorted.

If you know that the sorted order is going to be maintained, you can add that as a data set option:

data interleaved (sortedby=id);

   set a b;

   by id;

run;

If you then run a PROC CONTENTS, the sort indicator will be maintained.  However, the second related indicator (VALIDATED) will not be set because SAS has not validated the sorted order.

Finally, when you use the SORTEDBY data set option, you better be correct.  If you are wrong, the data will not be in order but subsequent PROC SORTs will be skipped.  There are ways around that, but it's better not to get into that situation in the first place.

Good luck.

View solution in original post


All Replies
Solution
‎04-07-2015 11:45 AM
Super User
Posts: 5,498

Re: Interleaving question Sort indicator

The DATA step has the potential to destroy the sorted order.  For example, this would be a legal program:

data new;

   set already_sorted;

   by id;

   if amount > 1000 then id='ABC';

run;

The new data set is not sorted, even though the incoming data set is sorted.

If you know that the sorted order is going to be maintained, you can add that as a data set option:

data interleaved (sortedby=id);

   set a b;

   by id;

run;

If you then run a PROC CONTENTS, the sort indicator will be maintained.  However, the second related indicator (VALIDATED) will not be set because SAS has not validated the sorted order.

Finally, when you use the SORTEDBY data set option, you better be correct.  If you are wrong, the data will not be in order but subsequent PROC SORTs will be skipped.  There are ways around that, but it's better not to get into that situation in the first place.

Good luck.

🔒 This topic is solved and locked.

Need further help from the community? Please ask a new question.

Discussion stats
  • 1 reply
  • 179 views
  • 0 likes
  • 2 in conversation