From: SMTP%"buda@star.enet.dec.com" 23-JUN-1993 11:17:24.69 To: EVERHART CC: Subj: Re: indexed file moving X-Newsgroups: comp.os.vms Subject: Re: indexed file moving Message-Id: <1993Jun21.211000.3435@e2big.mko.dec.com> From: buda@star.enet.dec.com (Mark A. Buda) Date: Mon, 21 Jun 1993 21:10:00 GMT Reply-To: buda@star.enet.dec.com (Mark A. Buda) Sender: usenet@e2big.mko.dec.com (Mr. USENET) Organization: OpenVMS Engineering X-Newsreader: mxrn 6.18-1 Lines: 33 To: Info-VAX@kl.sri.com X-Gateway-Source-Info: USENET >From buda Mon Jun 21 17:14:11 1993 To: "Glenn C. Everhart" Cc: Subject: Re: indexed file moving >I don't know of any general ways to move ISAM files so that the data >parts of the file are on a faster disk than the index parts. This is quite easy to do. Using a volume set and areas, you can specify where each area (by RVN) shoudl reside. This can be commonly done using an ESE-20 or RAM disk to host the index area and putting the data area onto a slower media. > Simple RMS ISAM files are not (far as I know, which isn't THAT far...:-) ) >structured so some simple trick of having some blocks of the file on >one disk, others on another, would be very helpful. Actually it is quite useful and not that uncommon. Since the index is the most common access part of the file, putting it on faster media allows faster access to the whole file! Of course global and local buffers are best used. I have mentioned thisat the DECUS talks I have done on RMS Performance, so next time I give an RMS talk, I expect you will be there, Glenn! :-) - mark