Another Factorial File Compression Experiment Using SAS

Continuing experimental work on SAS data set compression presented at NESUG in 2004, I designed another two-factor factorial experiment. My first factor compares the three kinds of data set compression offered by SAS on UNIX; the SAS DATA set OPTIONS COMPRESS=CHAR, COMPRESS=BINARY and SAS sequential format files created with the V9TAPE engine, three UNIX file compression algorithms; compress, gzip, and bzip2 and a control without any file compression. My second factor compares four kinds of SAS data sets; all character variables, all numeric variables, half character and half numeric, and all numeric in which LENGTHs shorter than 8 were used for smaller values. bzip2 minimized compressed file size for all four control SAS data sets. Only the three SAS file compression methods can be used to give other SAS users read access to compressed SAS data sets without giving them write permission to these files. SAS COMPRESS=BINARY reduced compressed file size more than SAS COMPRESS=CHAR on all four variable type treatments tested including SAS data sets containing only character variables.