Compress PDS – abend SE37 There are times when we face SE37 abend while updating a PDS for members. One such situation is compile jobs which generates/updates load in loadlib. You may face such abend for the loadlib. The following may be helpful in resolving If a PDS is in use for a long time and members are frequently changed, deleted, and new members created, it creates lot of unused gaps or spaces. You can compare this situation to fragmentation of disk in windows. Just like a defrag is required after sometime to free up unused space, similarily we need to compress PDS to free up unused space. Compressing a PDS actually rearranges members by using the unused free space To compress a PDS you can use the following steps Step 3: Provide the name of PDS which you wish to compress Step 5: Enter “Z” against the PDS you wish to compress