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* Use by a Business
@ 1994-05-30 07:55 Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Re: Use by a Business Paul M. Aoki <aoki@postgres.Berkeley.EDU>
0 siblings, 1 reply; 6+ messages in thread
From: Mark Metson @ 1994-05-30 07:55 UTC (permalink / raw)
To: legacy
I am unclear how the postgres license is to be interpreted where a business
is thinking of using it. Not 'distributing' it, but using it and placing
it on more than one machine. (Distributing it within the company therefore
to be construed as commercial distribution?) I am a consultant employed by
a Collection Agency to support and develop their computer systems. They
currently run a package I wrote for them in Business Basic, running under
S.C.O. Unix System V. The Basic and the Unix cost $2500 and $2300 (cant
recall which figure is for which of them). They do not wish to pay out
$4800 each time they bring up another machine, hence I propose to move them
to Linux. If I utilise postgres instead of Business Basic to rewrite the
package, where would we stand regarding postgres license? They do not intend,
nor, I suspect, desire, to distribute the package to other agencies. However
we would like to be able to write user-agents for clients to use in accessing
subsets of our data -- this need not require postgres though. Primarily we
need record-locking; it appears ingres and metalbase do not provide this
(at least for isam type databases) whereas postgres does. But postgres may
in many ways be overkill just to obtain that one capability; postgres seems
so powerful that if there is to be a charge for using it, we fear the charge
could be rather high; since we are only considering it due to this one
feature, we probably could not afford such a powerful solution.
They ARE perfectly willing to release all source code of anything they DO
distribute, its just they arent planning to distribute. Would they be
REQUIRED to distribute it to all agencies who express an interest in
obtaining the package, or would they just have to provide source and all
copyrights etc to anyone they DO distribute it to (probably no-one) ???
Blessed Be. -MarkM-
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^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Use by a Business
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
@ 1994-05-30 19:40 ` Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-30 19:47 ` Re: Use by a Business Michael Ubell <michael@montage.com>
1994-05-31 01:40 ` Re: Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
0 siblings, 2 replies; 6+ messages in thread
From: Paul M. Aoki @ 1994-05-30 19:40 UTC (permalink / raw)
To: Mark Metson <gpurdy@fox.nstn.ns.ca>; +Cc: legacy
Mark Metson <gpurdy@fox.nstn.ns.ca> writes:
> If I utilise postgres instead of Business Basic to rewrite the
> package, where would we stand regarding postgres license?
Permission to use, copy, modify, and distribute this software and its
documentation for educational, research, and non-profit purposes and
without fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright notice and
this permission notice appear in supporting documentation, and that
the name of the University of California not be used in advertising
or publicity pertaining to distribution of the software without
specific, written prior permission. Permission to incorporate this
software into commercial products can be obtained from the Campus
Software Office, 295 Evans Hall, University of California, Berkeley,
Ca., 94720. The University of California makes no representations
about the suitability of this software for any purpose. It is
provided "as is" without express or implied warranty.
offhand, i'd say if someone's making money from the construction
of a system, you should talk to the licensing people (just to be
safe).
personally, i would not sell a package to a client that contained
postgres (or university ingres, for that matter -- i once told the
last ingres chief programmer about a product that had ingres89
embedded in it and his reaction was priceless). i'd get a
commercial database. (but then, i'm the sort of person who'd say
that if my paycheck was on the line, i'd use bsd/386 instead of
linux, too.. i like linux, but.. :-)
> Primarily we
> need record-locking; it appears ingres and metalbase do not provide this
> (at least for isam type databases) whereas postgres does.
nope, postgres doesn't do record locking either. it does actually
have a multilevel escalating lock manager built in, but it isn't
used at the record level. it does do page-level locking for b-trees
but not for r-trees and heaps.
(montage has page-level locking for heaps.)
--
Paul M. Aoki | CS Div., Dept. of EECS, UCB | aoki@postgres.Berkeley.EDU
| Berkeley, CA 94720 | ...!uunet!ucbvax!aoki
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^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Use by a Business
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Re: Use by a Business Paul M. Aoki <aoki@postgres.Berkeley.EDU>
@ 1994-05-30 19:47 ` Michael Ubell <michael@montage.com>
1994-05-31 02:53 ` locking [was: Use by a Business] Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1 sibling, 1 reply; 6+ messages in thread
From: Michael Ubell @ 1994-05-30 19:47 UTC (permalink / raw)
To: Paul M. Aoki <aoki@postgres.Berkeley.EDU>; +Cc: Mark Metson <gpurdy@fox.nstn.ns.ca>; legacy
> it does do page-level locking for b-trees
>but not for r-trees and heaps.
Doing page locking on b-trees but not on the underlying heap does not really
buy you anything since if you do an update the whole heap table is locked so
things will be single threaded no matter what you do in the b-tree.
==============================================================================
To add/remove yourself to/from the POSTGRES mailing list: send mail with
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^ permalink raw reply [nested|flat] 6+ messages in thread
* locking [was: Use by a Business]
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Re: Use by a Business Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-30 19:47 ` Re: Use by a Business Michael Ubell <michael@montage.com>
@ 1994-05-31 02:53 ` Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-31 01:55 ` Re: locking [was: Use by a Business] Mark Metson <gpurdy@fox.nstn.ns.ca>
0 siblings, 1 reply; 6+ messages in thread
From: Paul M. Aoki @ 1994-05-31 02:53 UTC (permalink / raw)
To: Michael Ubell <michael@montage.com>; +Cc: Mark Metson <gpurdy@fox.nstn.ns.ca>; legacy
Michael Ubell <michael@montage.com> writes:
> > it does do page-level locking for b-trees but not for r-trees and heaps.
> Doing page locking on b-trees but not on the underlying heap does not really
> buy you anything since if you do an update the whole heap table is locked so
> things will be single threaded no matter what you do in the b-tree.
well, yes. to quote src/doc/implementation/am.me, written by mike
olson (now at montage):
Users of the access method interface routines need not
worry about locking. The access method routines acquire
(and, when appropriate, release) locks on relations in
response to scans and updates. Heap relations are protected
by two-phase relation level locks. Btree indices use
Lehman-Yao5 short-term locking for high concurrency, but
since the underlying relations are locked at the relation
level, index updates are serialized. Rtree indices use two-
phase relation-level locking.
5 Lehman, P., Yao, S., ``Efficient Locking for Concurrent
Operations on B-trees'', ACM Transactions on Database Sys-
tems, 6(4), December 1981.
but having working b-link trees reduces the amount of work some
hypothetical person would have to do to convert the core system to
page-level locking.
(not that the last two messages have had anything to do with what
the guy was asking..)
--
Paul M. Aoki | CS Div., Dept. of EECS, UCB | aoki@postgres.Berkeley.EDU
| Berkeley, CA 94720 | ...!uunet!ucbvax!aoki
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To add/remove yourself to/from the POSTGRES mailing list: send mail with
the subject line ADD or DEL to "postgres-request@postgres.Berkeley.EDU"
If this fails, send mail to "post_questions@postgres.Berkeley.EDU" and
a human will deal with it. DO NOT post to the "postgres" mailing list.
==============================================================================
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: locking [was: Use by a Business]
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Re: Use by a Business Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-30 19:47 ` Re: Use by a Business Michael Ubell <michael@montage.com>
1994-05-31 02:53 ` locking [was: Use by a Business] Paul M. Aoki <aoki@postgres.Berkeley.EDU>
@ 1994-05-31 01:55 ` Mark Metson <gpurdy@fox.nstn.ns.ca>
0 siblings, 0 replies; 6+ messages in thread
From: Mark Metson @ 1994-05-31 01:55 UTC (permalink / raw)
To: Paul M. Aoki <aoki@postgres.Berkeley.EDU>; +Cc: Michael Ubell <michael@montage.com>; legacy
On Mon, 30 May 1994, Paul M. Aoki wrote:
> Michael Ubell <michael@montage.com> writes:
...
> (not that the last two messages have had anything to do with what
> the guy was asking..)
...
Ah but they do, they do. Locking is the crux of the problem. I have a
complete application running at a Collection Agency in Business Basic
under SCO Unix System V. Standard code developed across a number of
employers in which when you edit a masterfile record the record is locked
using an 'EXTRACT' until unlocked using a READ or WRITE. Meanwhile it
sits on user's screen over lunch or until per-input timeouts realise
they've gone to lunch. There are two pricetags, $2500 and $2300, one for
new unix, one for new BASIC (can never recall which is which), total
$4800, which come up every time they think about computerising another
branch office. Assuming they have $4800 on hand, we'd all feel better if
they spent it on something more constructive, like buying hardware or
paying me. I wanted GNU instead of UNIX in the first place, but it wasnt
available back then. Now, the free unix I kept telling them was on the
horizon is here, we want to move to it. We also would like to move from
the BASIC if it'd be cheaper to rewrite than to buy a copy per possible
new site, and may HAVE to move from BASIC if we cannot get Business Basic
for Linux. I have just this day discovered some ALPHA code for running
SCO SysV executables under Linux, so possibly I might be able to stay
with BASIC, but if not, postgres is the only thing I've seen that might
be useable in its place, other than to take some standard ISAM code and
write a shared-memory record-locks-table or somesuch for it; and since
Linux kernel support for arbitrary locks has no
deadlock-detection/protection in it, I am rather wary of potential
deadlock situations if I try to add a key with one task while deleting a
key with another task in the same index; I suspect record-level locks on
the blocks ofa Btree would be in real deadlock danger in such scenarios.
I guess Business Basic spoiled me, I had never spent much thought on what
nifty tricks the language was taking care of for me in its
innocent-seeming record handling system.
Blessed Be. -MarkM-
==============================================================================
To add/remove yourself to/from the POSTGRES mailing list: send mail with
the subject line ADD or DEL to "postgres-request@postgres.Berkeley.EDU"
If this fails, send mail to "post_questions@postgres.Berkeley.EDU" and
a human will deal with it. DO NOT post to the "postgres" mailing list.
==============================================================================
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: Use by a Business
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Re: Use by a Business Paul M. Aoki <aoki@postgres.Berkeley.EDU>
@ 1994-05-31 01:40 ` Mark Metson <gpurdy@fox.nstn.ns.ca>
1 sibling, 0 replies; 6+ messages in thread
From: Mark Metson @ 1994-05-31 01:40 UTC (permalink / raw)
To: Paul M. Aoki <aoki@postgres.Berkeley.EDU>; +Cc: legacy
Perhaps I dont really specifically need 'record locking' per se. I am
just used to thinking in such terms because in Business Basic when I call
up a record onscreen in modify mode for a user and dont want its contents
changing behind their back, I "EXTRACT" the record. I dont like the idea
of the entire (for example) debt-masterfile or client-masterfile locked
because one bozo went to lunch with one record onscreen in
potentially-modifying mode, so the BASIC's approach of locking the record
seemed a natural approach.
--
Mark Metson How many mystics does it take to bring Peace on Earth?
gpurdy@fox.nstn.ns.ca Only one - but each one has to do it for themself.....
==============================================================================
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==============================================================================
^ permalink raw reply [nested|flat] 6+ messages in thread
end of thread, other threads:[~1994-05-31 02:53 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
1994-05-30 07:55 Use by a Business Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-30 19:40 ` Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-30 19:47 ` Michael Ubell <michael@montage.com>
1994-05-31 02:53 ` locking [was: Use by a Business] Paul M. Aoki <aoki@postgres.Berkeley.EDU>
1994-05-31 01:55 ` Re: locking [was: Use by a Business] Mark Metson <gpurdy@fox.nstn.ns.ca>
1994-05-31 01:40 ` Mark Metson <gpurdy@fox.nstn.ns.ca>
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