11-20-2014 04:38 AM
as per the documentation of SAS (http://support.sas.com/documentation/cdl/en/basess/58133/HTML/default/viewer.htm#a001304305.htm),
under Understanding the MERGE Statement it is stated:
"SAS-data-set-list is the names of two or more SAS data sets to merge. The list may contain any number of data sets"
11-20-2014 04:39 AM
According to Step-by-Step Programming with Base SAS(R) Software, there seems to be no fixed limit:
The list may contain any number of data sets.
But you may run out of resources with very large numbers of datasets; you can only confirm this by testing.