>>> Member names. The reason would be that a PDS directory is maintainedin order, > and the directory is always kept compressed.
Tom, Thanks for the info and as mentioned earlier DFSORT has the ability of sorting the member names in ascending/descending order. Here is a sample to show just the sorting of pds member names. //STEP0100 EXEC PGM=IKJEFT01 //SYSTSPRT DD DSN=&&MBRS,DISP=(,PASS),SPACE=(CYL,(5,5),RLSE), // DCB=(LRECL=80,RECFM=FB,BLKSIZE=0),UNIT=SYSDA //SYSTSIN DD * LISTDS 'USERID.PDS' MEMBERS //* //STEP0200 EXEC PGM=SORT //SYSOUT DD SYSOUT=* //SORTIN DD DISP=SHR,DSN=&&MBRS //SORTOUT DD SYSOUT=* //SYSIN DD * INREC IFTHEN=(WHEN=GROUP,BEGIN=(1,11,CH,EQ,C'--MEMBERS--'), END=(1,5,CH,EQ,C'READY'),PUSH=(81:ID=1)), IFTHEN=(WHEN=(1,11,CH,EQ,C'--MEMBERS--',OR, 1,05,CH,EQ,C'READY'),OVERLAY=(81:8X)) SORT FIELDS=(81,1,CH,A, 03,08,CH,D),EQUALS //* Thanks, Kolusu DFSORT Development IBM Corporation IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> wrote on 11/20/2015 09:54:59 AM: > From: Tom Marchant <0000000a2a8c2020-dmarc-requ...@listserv.ua.edu> > To: IBM-MAIN@LISTSERV.UA.EDU > Date: 11/20/2015 09:55 AM > Subject: Re: Deleting all members of a pds > Sent by: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> > > On Fri, 20 Nov 2015 08:11:08 -0700, Sri h Kolusu wrote: > > >>>>Does it at least sort the list in descending order? > > > >Descending order of what? member names or Size? Why exactly do you need to > >sort the list ? Do you think it would make a difference to the directory > >blocks? > > Member names. The reason would be that a PDS directory is maintainedin order, > and the directory is always kept compressed. > > Whenever a member is deleted from a PDS, the following directory > entries are all > shifted to the left. Then, if there is enough space at the end of > that directory > block, the first entry from the next block is moved to that space, > and the process > repeats to the end of the directory. > > As a result, there is less I/O if they are deleted starting at the > end of the directory. > This is especially true if there are a lot of members in the PDS. > > -- > Tom Marchant > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN