Dear all,

I am confused about SAS' usage of storage: When do I need space in the work library, and when do I need it in the permanent library ?

I will have to handle some very large data sets, and have just started with a roughly 800MB/3.5Mio observation dataset (PC). I have two partitions on my computer, and had assigned the permanent library to the partition with less free space (D:), assuming that I would need just enough space for accomodating the data set.

However, even though I could not find a physical file causing the problem, a data step with a merge, that did not change the size of the permanent data set, resulted drive D: running out of space. When I reallocated the permanent library to the larger partition, all went well. Does anybody know, how SAS handles space in the data step, i.e.:

- When does it use the work library ? - When does it use the permanent library instead? - Where does it write onto the disk, if the disk gets fuller and fuller, while I can't find the file that causes this ?

Regards, Ulrike