If the library is frequently updated, LLA is indeed no choice. LLA freezes the directory in storage until it is refreshed. This means that every update will be invisible until LLA (or all LLAs sharing the library) has been refreshed. A truly unworkable situation, I suppose.
Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Kreiter IBM-Main Sent: 28 April, 2016 15:32 To: [email protected] Subject: Re: PDS I/O Performance Improvement Thanks everyone for your suggestions. I'll test some of these suggestions with the user and see what the results are. I'm going to start with a PDSE test as I think that is the quickest thing to try. The parmlib is updated frequently so caching the directory with LLA probably isn't the best plan. As I understand the user's description of the job, they are using PROJCL to generate some kind of reporting that is expanding JCL and pulling in the parms from this PDS. ----- Original Message ----- From: "Kreiter IBM-Main" <[email protected]> To: [email protected] Sent: Thursday, April 28, 2016 8:32:56 AM Subject: PDS I/O Performance Improvement Hello, I'm looking for some suggestions on how to possibly improve I/O performance to a PDS. A user is running a job that is reading a large parmlib (through PROJCL I believe). I think the access is random rather than sequential. The parmlib has ~180,000 members is has an LRECL of 80/BLKSIZE of 27,920. The performance team has reviewed a found ~ 6ms response time to the volume that houses the PDS with most of the time being connect time. Thanks, Chuck ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
