Reza, For me it's not an exception, because I'm in the business of saving IO and not space )my employer would not like me to save space).
I see nothing wrong with compressed datasets going to ML2, especially if they are unlikely to be touched again before they are deleted. ML2 is usually on media that is cheaper than ML0. Actually what I think is quite smart is that they are sending it straight to ML2 without migrating to ML1 first. There's almost zero net sum gain migrating compressed datasets to ML1. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of > R Hey > Sent: Wednesday, February 24, 2010 12:16 AM > To: [email protected] > Subject: Re: [IBM-MAIN] SMS compression cost & size > > Ron, > > Your example is an 'exception', it was decided to do it for that DS to gain > the > benefit. That's OK by me. > > It wasn't decided to COMP all VSAM/PS(FB/VB) DS that are over 5 CYL, which > is the case I question. I've seen thousands of GDS, under 5 Cyl, being > COMP'd, & they quickly go to ML2, so they are not read many times. This > doesn't make sense to me, if one is short on CPU. > > I should have said: > I don't see why anyone would compress ALL DS under 500 Cyl these days, > just to save space, when one is short on CPU. > > > there is more to compression than just the size of the dataset. > > Amen. > > Rgds, > Rez > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
