Larry,

My understanding is that YES, the records shuffle up, otherwise know as
Migrating Secondaries. If doing a serial read of a master set and deleting
entries, the code should look like this:

mode 2 read, exit if eof
test for delete needed,delete
if deleted previous record, do a mode 1 read - if err 17 go to mode 2 read
if no error on mode 1, goto delete test

The alternative is to do multiple passes (inefficient), or sort the entries
qualified for delete, and do mode 7 reads, which will find the entries
irrespective of migration.

hth
jp
----- Original Message -----
From: "Larry Barnes" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, June 17, 2003 6:42 AM
Subject: [HP3000-L] Primaries, Secondaries, and synonym chains, oh my!


Help with Image


Say you have a record that lives at address 100, a second record tries to
write to the same address, but is sent to record 133 with a pointer written
at record 100.  Now this process continues and we now have a synonym chain.

If you have a program that deletes records by record address (bad choice in
my opinion), do the records move up in the chain?  (i.e. the record at
location 133 is deleted, what happens to the records further down in the
chain, do the move up 1 slot? (bad choice of words I know)

Or

say you delete record 100, does record 133 move to slot 100?


It's been awhile since I've written code and my memory isn't that clear on
the subject anymore.


Larry A. Barnes
Systems Administrator - HP3000
Coldwater Creek Inc.

Shop today at Coldwater Creek http://www.coldwatercreek.com

"Even if you're on the right track, you'll get run over if you just sit
there." - Will Rogers


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