> -----Original Message----- > From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On > Behalf Of Alan Altmark > Sent: Monday, September 11, 2006 12:53 PM > To: [email protected] > Subject: Re: FCP over ECKD performance advantage - why? >
<snip> > Useless? While the operating systems may not be exploiting > the full power > of ECKD, applications can. I don't know if DB2 and VSAM > still use keys on > the disk to search for data or not. > At least on the OS side (starting with OS/VS1, OS/MVS), VSAM never used hardware keys. It always preformatted CIs or CAs with a specific hardware record size without keys. ISAM may have used hardware keys, I don't remember. VSAM KSDS has always been a B+ tree (IIRC). DB2 uses LDSes, accessed via something called "media manager", which is not documented to the unwashed masses such as myself. <snip> > > Alan Altmark > z/VM Development > IBM Endicott -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited. ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
