Speed Merges with Key Merging and the _IORC_ Variable

Abstract

The key mege (A.K.A. _IORC_ merge) is an efficiency technique. It is a method of merging two files without having to perform a slow, and disk-space-consuming, pre-sorting of the files. Because this merge does not require pre-sorting of the files to be merged, it can be faster and uses less disk space than a by merge. The _IORC_ merge is considered one of the "Table Lookup Techniques" and as such is a competitive technique for “by merges”, formats, if-else if blocks, key-indexing, bitmapping, hashing and SQL joins. It is a useful technique for SAS programmers because it is fairly fast (faster than a “by merge”) and easy to understand. Additionally, _IORC_ merging is part of the material in the SAS® certification exam. This paper accompanies an animated presentation at NESUG and can not duplicate the animated effect. It will outline the features of the _IORC_, as were presented. More material can be found in the excellent articles found in the on-line SUGI proceedings and listed in the reference section of this paper.