Charles: Are you saying that copying 13350*ABC to 13351*ABC wouldn't properly update the indexes? Or is CNAME using some obscure method of updating which bypasses the normal I/O that indexing handles?
Bill > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Stevenson, > Charles > Sent: Friday, July 23, 2004 6:57 AM > To: [EMAIL PROTECTED] > Subject: RE: [U2] Longstanding aversion to CNAME? > > > UV10 STILL DOES NOT UPDATE INDEXES if the index is part of the ID. > > > From: Norman, David (SAAS) > > > > In UV9.4 CNAME didn't update secondary indexes, which left a bit of > > a mess behind. This has now been fixed, probably from 9.6. > > > > Example. A 2-part id: [internal-date]*[something] indexed on date ( > @ID['*',1,1] or FIELD(@ID,'*',1) ) > > Changing a "0" to a "1" in a date in a particular id: > > CNAME file 13350*ABC,13351*ABC > > will leave old, nonexistant id "13350*ABC" indexed under date "13350" > and will not add the new id to "13351". > > > IBM knows this (probably forwarded from the Vmark days), but resolutely > will not fix it because the underlying i/o routines used by CNAME are > different from the norm and won't easily support the change. This > list's archives will support that claim. > > One could reasonably restate that as, "It's too hard to fix, so just > live with the inherent data integrity vulnerability." > Or even, "Help, help we're being oppressed. Come see the vulnerability > inherent in the system." > > Chuck Stevenson > > > P.S. As for speed, for type-1 & -19 CNAME is faster than other > read/write/delete schemes one could program. I *believe* it invokes a > unix "mv" command which simply repoints the inode without actually > moving any files. Similar on MS. > > P.P.S. I recall CNAME was originally a PRIMOS command similar to unix > mv. Information just borrowed the name and handled type-1 ( UFDs > (UserFileDirectories) ) with the primos mechanism, and used its own > mechanism for hashed records. > ------- > u2-users mailing list > [EMAIL PROTECTED] > To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [EMAIL PROTECTED] To unsubscribe please visit http://listserver.u2ug.org/
