W dniu 2010-04-14 16:18, McKown, John pisze:
I'm just curious as to why IBM chose to create the VRRN type of VSAM file. I understand a
normal RRN (NUMBERED). In both cases, the record is addessed by relative record number.
But I don't really see the need for a VRRN. Why not just have a KSDS with a 4 byte key at
offset 0? Is it to remove the relative record number from the user record?And, I guess,
so that you can't change the "record number" by updating the key. Just curious.
What is VRRN? Do you mean RRDS with variable length records? AFAIK it is
usually called vRRDS. In fact it *is* KSDS under the cover - it has
index, you specify freespace, etc.
Why vRRDS? Convenience? It's easier for existing apps.
BTW: In the old days there were (were = support dropped) option in
COBOL allowing "emulation" of vRRDS on KSDS. I guess it was created
before vRRDS was created. In this case you had to define KSDS you all
the utilities except the application did treat the dataset as regular KSDS.
--
Radoslaw Skorupka
Lodz, Poland
--
BRE Bank SA
ul. Senatorska 18
00-950 Warszawa
www.brebank.pl
Sd Rejonowy dla m. st. Warszawy
XII Wydzia Gospodarczy Krajowego Rejestru Sdowego,
nr rejestru przedsibiorców KRS 0000025237
NIP: 526-021-50-88
Wedug stanu na dzie 01.01.2009 r. kapita zakadowy BRE Banku SA (w caoci
wpacony) wynosi 118.763.528 zotych. W zwizku z realizacj warunkowego
podwyszenia kapitau zakadowego, na podstawie uchway XXI WZ z dnia 16 marca
2008r., oraz uchway XVI NWZ z dnia 27 padziernika 2008r., moe ulec
podwyszeniu do kwoty 123.763.528 z. Akcje w podwyszonym kapitale zakadowym
BRE Banku SA bd w caoci opacone.
----------------------------------------------------------------------
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
