Talk:Concatenation Operations with PROC APPEND

From sasCommunity

It is not at all a given that BASE= should point to the longer of the two data sets and DATA= to the shorter. One might do the opposite and use the shorter as the base

• because one has been established as the master and the other is merely a container for a subset
• to preserve structural properties (such as variable order)
• because the two are in different libraries and the concatenation belongs in one of those and not the other
• to maintain BY group ordering
• to preserve a name for the concatenation without the need to invoke PROC DATASETS to swap names

If none of these concerns arise, and one is indifferent about the order, it does make sense to reduce I/O by making the larger data set the base.

Howles 23:46, 29 May 2007 (EDT)