@clqa wrote:
is proc format permanent?
Yes, no and maybe.
A format can be permanently assigned to a variable. Typically in a data step but other procedures can do so. Proc DATASETS is intended to change characteristics of a data set such as variable formats, variable names, variable labels as some other things. Most procedures that produce output sets involving the formatted value of a variable will have that format "permanently" assigned in the output set even though it wasn't in the input.
While the format may be permanently assigned to a variable the format itself might be temporary. You can create custom formats with proc format. Default will place the format definition in the WORK library. So a permanent data set with such a format may not find the format definition if the format code isn't run in the next SAS session. There are options with Proc Format to write the format definitions to a library and then tell SAS to find the definitions in that location.
A format can also be used temporarily for specific output at need. For example run this example and see the difference in the output.
The SASHELP.CLASS data set should be included in your installation.
Proc freq data=sashelp.class;
title "Default format";
tables height;
run;
Proc freq data=sashelp.class;
title "Assigned F2 Format";
tables height;
format height f2.;
run;title;
