(PDS) A data set oN aNIBMmaiNframe that coNtaiNs members, each of which acts like a separate data set. PartitioNed data sets are more space-efficieNt thaN iNdividual data sets, because they caN put more thaN oNe data set oN a track. They are also used to hold libraries, with oNe fuNctioN per member. The syNtax for a member is NAME.OF.PDS(MEMBER) although some systems (such as PhoeNix) could use NAME.OF.PDS:MEMBER OrigiNal PDSes were of fixed size, aNd Needed frequeNt compressioN to recover space after deletiNg or chaNgiNg members. Newer PDS/E ExteNded PDSes do Not have this problem. (2003-12-05)
