HDTenEightyP/NetNews huggingface dataset:
From: rcbc@fafnir.cs.cornell.edu (Robert Cooper)
Subject: Re: Hot Standby DBMS's
Reply-To: rcbc@cs.cornell.edu
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Wed, 26 Aug 1992 17:54:02 GMT

> >The latter approach has a number of tricky problems that people have
> >pointed out. The main one is ensuring that concurrency control is
> >coordinated between the replicated data managers so that exactly the same
> >order of data updates and accesses occurs on both replicas.
> 
> Fine, but "coordination of concurrency control" is not required to 
> achieve that goal if you use distributed transactions.  "Coordination 
> of the input streams" may however be required to prevent deadlock 
> causing race conditions.

Let's say we are updating bank account A at the primary and backup.
I was envisaging something like this:

   top-level-trans
      parallel begin
         sub-trans-1
            update A on server 1
         end
         sub-trans-2
            update A on server 2
         end
      end
   end

In which case we could not guarantee (without knowledge of the scheduling
and concurrency control internal to server 1 and server 2) whether 
the updates to A would be serialized identically at the two servers, given
that other transactions might be simultaneously updating those account
records, etc. We'd want to ensure that both subtransactions claimed the
same locks in the same order with respect to competing transactions.

Instead we could do this:

   top-level-trans
      serial-begin
         sub-trans-1
            update A on server 1
         end
   
         sub-trans-2
            apply results from sub-trans-1 to A on server 2
         end
      end
   end

In this case we perform the logical operation on A at server 1, record the
modified data items and apply those updates to server 2. Basically what
this code is just a roundabout way of reading the journal from server 1 and
applying the updates it records to server 2. 

I presume this is Dan Hepner's point, and he's right. Distributed nested
transaction systems look like they will allow people to program this
solution. My only comment would be that this doesn't look much easier than
the solutions people are coming up with using Isis and non-distributed
transactions. 

Has anyone actually implemented a primary-backup database using distributed
transactions in this way? Are nested transactions (or at least some
conditional commit mechanism) part of Tuxedo, Encina, etc?

       -- Robert
--
--
From: john@jlc.mv.com (John Leslie)
Newsgroups: comp.databases
Subject: Re: OODB Experiences/Opinions (Objectivity
Date: 23 Aug 92 17:42:27 GMT
Organization: John Leslie Consulting, Milford NH

In article <l97gf2INN214@jethro.Corp.Sun.COM> tmhoff@oogoody.Corp.Sun.COM 
(Todd Hoff) writes:
>
>I'd like to be somewhat of an apologist for product reviewers. I don't
>condone sloppy work, but as someone who has written several product reviews
>I can attest that it is not easy to do a good thorough review. 

   I'll second that!  I've written two that I can remember.

>First the pay is lousy.

   Big time!  If you're not careful, it can fall below $10 per _day_!
I did it (many years ago) believing having my name attached to reviews
would pay off and bring in business.  It hasn't (yet).

>Second, often your deadlines are tight for a variety of reasons.
>Third, many products make it hard to do a good review... 
>The actual writing of a review is tough as well... 
>Do you spend the time to try and find people who have used the product?

   For goodness sake, Todd, why not?

   How much time can it take to post a message saying, "I'm writing a
review of X, Y, and Z.  Could some folks who have experience with these
programs please send me their e-mail addresses?"

John Leslie <john@jlc.mv.com>
From: lapworth@mizar.usc.edu (Bill Lapworth)
Newsgroups: comp.databases
Subject: Clipper 5.01 error with dos 5.0 loaded high
Date: 27 Aug 1992 14:40:32 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: mizar.usc.edu

Sometimes when I run a clipper created .exe file, I get this error msg:
  error est0001: Illegal format in loadable file

Until today using dos 5.0 loadfix to execute the file OR not loading 
dos high would run the program ok.  But today I used loadfix and got
the same error.  My pc is pretty stable except for this problem, does
anybody have any clues?


Newsgroups: comp.databases
From: jka@windshear.larc.nasa.gov (J. Keith Alston)
Subject: List Popups from dbase 4 screens
Organization: NASA Langley Research Center, Hampton, VA  USA
Date: Wed, 26 Aug 1992 15:07:27 GMT

Hi,
  I am writing a dbase 4 application, and I wish to use a popup, on a data
  entry screen, which gives me a list of possible values for a field.
  I want this popup
  to pop up either when the cursor reaches the field on the screen or by a
  function key press. The list of posible values is contained in another
  table. When the selection is made from the popup I want the selected
  value to appear in the screen field and the cursor to go to the next
  field. Any Ideas on how this could possibly be done, would be greatly
  appreciated.

-- 
************************      Don't just do it!     ***********************
Lockheed Eng. and Sci. Co./Nasa Larc|J. Keith Alston jka@windshear.larc.nasa.gov
Newsgroups: comp.databases,comp.databases.informix
From: sethg@dcatlas.dot.gov (Seth Grimes)
Subject: Re: Informix vs. Oracle 
Keywords: informix oracle database rdbms
Organization: U.S Dept. of Transportation
Date: Thu, 27 Aug 1992 11:45:56 GMT

mathews@bones.ecs.umass.edu (Mathew J Mathews) writes:

>My boss was recently told by a salesman that Informix would soon be the new
>RDBMS standard on top of Oracle.  Needless to say, she asked me to investigate.
>I have not been able to find very much written on Informix.  Could anyone
>give me their 2 cents, and/or point me to a good source of info?

I say this is a typical salesperson BS.  Oracle is out in the lead by far,
especially because Informix has ignored or abandoned important market 
sectors like VAX/VMS.  Informix is a Unix DBMS; Oracle is on loads of
platforms.  Oracle is integrating their DBMS with lots of applications;
does Informix sell anything but the DBMS.  And lastly, Oracle has a great
marketing department, although their hype caught up with them last summer
when some of their accounting practices like premature recording of sales
and penchant for vaporware became exposed.  How else could such a mediocre
product have captured so much of the market?

If the salesperson meant that Informix would overtake Oracle as a technical
standard, well, Oracle never was a technical leader, except in their ability
to get their product to run on a spectrum of platforms, and it's not gaining
on competitors like Ingres and Sybase technically, either.

Seth Grimes, dcatlas!sethg@uunet.uu.net
Automated Sciences Group (U.S. Dept. of Transportation)
Xref: sparky comp.databases:6324 comp.databases.theory:390 comp.databases.oracle:1376
From: limsoon@saul.cis.upenn.edu (Limsoon Wong)
Newsgroups: comp.databases,comp.databases.theory,comp.databases.oracle
Subject: Re: Is this a bug or a limitation of the SQL language
Date: 26 Aug 92 01:40:30 GMT
Followup-To: comp.databases
Organization: University of Pennsylvania

>>>   The problem is that SQL is a poorly defined laguage.  Read Date's
>>>   "Critique Of The SQL Language".  There are numerous examples like yours.

Can someone kindly supply me a reference to this article?

                                    Thanks,
                                    limsoon@saul.cis.upenn.edu



Newsgroups: comp.databases
From: eric@desktalk.com (Eric Lieber)
Subject: Ingres - inserting date & time values
Reply-To: eric@desktalk.com
Organization: Desktalk Systems Inc.
Date: Fri, 28 Aug 1992 20:39:02 GMT

I am posting this because I do not have Ingres yet and therefore I cannot try itout myself.

I want to insert a datetime value into a table. The format I have to use is:
	"yyyy-mm-dd hh24:mi:ss"
where hh24 is the 24 clock , (13:00 = 1:00 pm)

After reading the manual, I assume that the  II_DATE_FORMAT varable must
 be to set to  'SWEDEN/FINLAND'.

 The question is will Ingres  accept the following:
 insert into test_table (date_col)
           values (	"1992-12-31 13:45:59");

Thanx for any info.

ps. isn't it amazing that none of the 4 databases (sybase, oracle, informix and ingress) have the same datetime definitions when creating a table and  same format when inserting a value!!!!!! 

Eric Lieber
DeskTalk Systems
Torrance, CA
eric@desktalk.com
(310) 323 5998 ext. 124
From: chris@yen.imsi.com (Chris Payne)
Newsgroups: comp.databases
Subject: Re: Hot Standby DBMS's
Date: 28 Aug 92 14:16:34 GMT
Organization: Moore Capital Management
In-reply-to: dhepner@cup.hp.com's message of 26 Aug 92 00:30:14 GMT
Originator: chris@yen


dhepner@cup.hp.com (Dan Hepner) writes:

   > One clean solution to the hot-backup equivalence problem is to
   >serialize the request stream.  Guarantee that when a credit precedes a
   >debit on one db server, it precedes the debit on all active servers.

   If this advice "credit must always precede debit" is not followed you 
   might get deadlocks even without replication.  However, this is insufficient 
   to prevent the other kind of out-of-order deadlocks.  What you have to 
   guarantee is that a transaction will acquire locks in a specified order 
   across copies.  I.e. execution of credit on copy 1 must always complete 
   before beginning on copy 2.

Here's the idea: serialize & fork the db request stream.  Each hot
standby database will receive the same transactions in the same order.
Other receiver(s) can take the same stream and keep it for posterity.

Handling multiple requests in parallel is a critical feature of modern
db's -- you can't afford to force every client's requests into a
single serialized stream.  As a result, you can't guarantee that the
interactions between the requests of various clients will be
duplicated on each hot standby server.  But, hey, if there's a
possible problem (as in lock ordering), then the application is
already in trouble.  Ensuring this level of server-equivalence on the
server side would reduce performance.

   >If you want to catch-up a server which is down periodically, keep a
   >copy of the request stream.

   How would you guarantee that transactions will be executed in the same
   serial order as was implied by the online system?  As has been pointed
   out, such a guarantee is required to keep the copies synchronized.

Unless you're worried about the non-serial nature of the server
itself, this is trivial, right?

/c (chris@imsi.com)
Xref: sparky comp.databases:6419 comp.databases.theory:425 comp.databases.oracle:1423
From: jalbert@IRO.UMontreal.CA (Francois Jalbert)
Newsgroups: comp.databases,comp.databases.theory,comp.databases.oracle
Subject: Objects and Oracle?
Date: 28 Aug 92 21:44:43 GMT
Reply-To: jalbert@IRO.UMontreal.CA (Francois Jalbert)
Organization: Universite de Montreal

Greetings all!

Our company develops software to run under Windows using the toolbook package 
in the early development phases. We do everything using objects and fairly 
complex inheritance schemes. Our current task is to develop some software to 
act as a front end to some relational database system. We are currently trying 
to figure out if Oracle might do the job for us. We phoned the local Oracle 
outfit but their answers were very vague, to say the least. I hope that by 
asking to net, somebody out there will know more than our local Oracle folks. 

Primarily, the database manager we seek should

  - be a true RDBMS
  - manage table creation and updates using SQL commands
  - run under Windows 3.1 on top of DOS 5.0
  - be callable from C (or C++) according to the DB2 standard of embedded SQL
  - support referential integrity, transaction security (commit rollback),
    multiusers, networks, to name the few I can think of at the moment.

We discarded DBase since it's not really SQL at the root, and it's too much 
micro oriented. Our customers are more the Oracle, Informix, Ingres types.

If Oracle could only have offered us SQL*form, SQL*report, and other "closed" 
means of access, we would immediately have discarded it. But we recently heard 
about Oracle Card and Oracle Access. These last two tools might make Oracle 
open enough for our needs. Let's be clear about this, we want to keep the full 
control of our Windows application running on Novell by doing all the interface 
stuff using Borland C++ and toolbook. The key word I constantly hear in the 
office these days is "open". My understanding is that DB experts programming in 
C are fully aware of what this term implies. (I'm no DB expert) 

I understand Oracle Card is related to Windows. Do we need that at all? Is it 
just a fancy Windows remake of old stuff, ie SQL*form and/or SQL*report? In 
which case we would never touch it.

Oracle Access seems to be a revamped version of Pro-C. What are the differences 
between the two? Is one better for objects than the other? For Windows?

I guess what we need is a way to access the power of SQL and RDBMS from within 
our own Windows applications. If anybody has played with those ideas and has 
something to report, please do so! We are also thinking about some small 
independent products that also boast of full SQL support, but Oracle is a big 
name and might look good on our company's record. We hope it won't prove too 
closed for our need. We are really new to DB stuff.

Thank you very much for any advice, Franky
From: joet@dcatlas.dot.gov (Joe Trott)
Subject: Re: Simple Question on Paradox
Organization: U.S Dept. of Transportation
Date: Thu, 27 Aug 1992 20:36:15 GMT


If this is to be a multi-user application, and the table to be appended is
_NOT_ a temporary scratch table, RTFM on the subject of Form Locking.  You
_cannot_ override a Paradox form lock.  If the table you are adding _to_
is to be accessed simultaneously with a form, you will not be able to
append to the table by any means _but_ that form if anyone is coediting it.
You must write a script to SCAN the input table and use COPYTOARRAY before
moving to the destination table, _picking the desired form_, Coediting, and
using a COPYFROMARRAY.  Don't forget to deal with possible key violations,
and have fun.

-JTT
From: DEVRIES@NAUVAX.UCC.NAU.EDU (Ernie DeVries)
Newsgroups: comp.databases
Subject: Re: Listing .VAL and SET files HOW?
Date: 2 Sep 92 18:02:09 GMT

Paralex by Kallista is a commercial product that does this quite well.

If you want to create your own, the basic script outline is:

1) Create an array to hold the values you'll be getting
2) Enter "Edit" mode in the table you want
3) use {menu} {ValCheck} {Define} Enter to get into ValChecks for the
   current field, then choose the type of val check that you want.
4) Store its current value in the array using array[1]=menuchoice().
5) Use the Esc command as many times as necessary to backup to step 3,
   then repeat for the next val check option.
6) When you get them all, move to the table image where you want to
   store the values and use CopyFrom Array to put them into a record.

This gets a little hairy with ValChecks that have multiple options like
lookupandfill, but it can be done.

I must add that I think it is ridiculous that this feature is not built
into the tools menu in Paradox.  Of course, I've been telling Borland
since version 2.0 that they need to provide a built-in way to print
report definitions and they haven't done that yet either.

--Boundary (ID ugIFCoZVzrkXpw0IdsveHQ)--
+========================================================+
|     /\                   Ernie DeVries                 |
|    /  \/\      Academic/Personal Computer Services     |
| /\/    \ \/\       DeVries@nauvax.ucc.nau.edu          |
|   Northern Arizona University   "The Mountain Campus"  |
+========================================================+
Newsgroups: comp.databases,comp.sys.dec
From: ffang@newsuiowa.edu (Francis Fang)
Subject: DAL Server for DECsystem 5000/200?
Date: Sun, 30 Aug 1992 16:29:52 GMT
Organization: University of Iowa, Iowa City, IA, USA
X-Newsreader: Tin 1.1 PL3

I'm currently running INFORMIX Online 4.0 on a DECsystem 5000/200. The
menu system of the application using the online engine is extremely
cumbersome and I would like to see if I can extract, update, and insert
new information directly from online on my Mcaintoshes.

The best solution would be to have a DAL server running on the DEC with
client software (written in 4D, Hypercard, or some other
Hyperscript/Database software).

I have spoken to informix and they seem to think that the only solution
is to run I-NET, I-STAR and use Datalink & Wingz.

Does anyone know if there is a general purpose (non-dependent on client
software) DAL server available that runs on a DECsystem running Ultrix
4.2? If not are there many folks running the configuration as suggested
above by informix?

Any info would be greatly appreciated.

Please post followups or reply to ffang@grover.printing.uiowa.edu.
From: thdhub!prl01%cphpdev1.homedepot.com@uunet.UU.NET (Livsey Renee)
Newsgroups: comp.databases.informix
Subject: <No Subject Supplied>
Date: 3 Sep 92 20:28:07 GMT
Reply-To: thdhub!prl01%cphpdev1.homedepot.com@uunet.UU.NET (Livsey Renee)
X-Informix-List-ID: <list.1428>


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>From: Livsey Renee <prl01@cphpdev1.homedepot.com>
Posted-Date: Thu, 3 Sep 92 13:54:36 EDT
Received-Date: Thu, 3 Sep 92 13:54:36 -0400
Message-Id: <9209031754.AA29591@cphpdev1.homedepot.com>
Subject: RCS headers in 4gl and HP Termcap
To: informix_list@rmy.emory.edu
Date: Thu, 3 Sep 92 13:54:36 EDT
Mailer: Elm [revision: 66.25]

We are looking for ways to utilize RCS in our 4GL.  The header information
will not display an ident after it is checked out.

We also need a HP Windows terminal termcap.  Please give me a call if you can
be of any assistance.

Thanks,

Renee Livsey
Home Depot
(404) 433-8211 x5298.
From: berit@tglobe2.tollpost-globe (Berit A Flataboe)
Newsgroups: comp.databases.informix
Subject: Distribution of data/table information changes and creates.
Date: 4 Sep 92 11:36:53 GMT
Reply-To: berit@tglobe2.UUCP (Berit A Flataboe)
Distribution: world
Organization: TOLLPOST-GLOBE AS, Systems Department, N-6300 Aandalsnes, Norway

DISTRIBUTION OF DATA/TABLE INFORMATION CHANGES AND CREATES

Does anyone out there have routines for distribution of data/table
information changes and creates which they want to share with us. We are
about to begin managing 30 online systems in different places all around
Norway. Our databases will be much the same in all 30 online systems,
it's mostly the tablesize which will be different.

Berit Anita Flataboe Roedven
TOLLPOST-GLOBE AS, Systems Department, PO 100, N6301 ]NDALSNES, NORWAY
E-mail: ...!nuug!tglobe2!berit, Phone : +47 72 26 673, Fax: +47 72 26 694

Newsgroups: comp.databases.informix
From: ashaw@cbnewsg.cb.att.com (andrew.shaw)
Subject: I am a stupid (was Online Performance Degradation)
Organization: AT&T
Date: Wed, 2 Sep 1992 13:14:12 GMT

Now that I have had some sleep, I realize that I should expect logN
behaviour: if the number of adds/minute falls off as log(t), then
the time for each add increases as log(t), which we are obviously
never going to better.

Several people have commented that the solution is to drop the indexes,
do the adds, and then rebuild the indexes.  Unfortunately I cannot do
this, as the adds come in unpredictably, and other processes will be
doing lookups at all times.

So it appears that Informix is doing a wonderful job, and there is
nothing else to be done.  I think I will try to precisely characterize
the curve, just to make sure logN is in fact correct.

Thanks to all who responded,

	Andrew Shaw
	AT&T Bell Labs
Lines: 23
Date: Thu, 27 Aug 92 09:29:21 MDT
From: kelly@baloo.ee.byu.edu (J. Kelly Flanagan)
Newsgroups: comp.databases.informix
Subject: TPC and Informix


	Please excuse any ignorance I show, but I have a question or
	two or three:

	How simple is Informix to install on a 486 machine running
	UNIX?  I can run Interactive SYSV R3.2 or DELL UNIX SYSV R4.

	I keep hearing about tuning the database, is this required?
	How difficult is this to do?

	Will the TPC-A and TPC-B benchmarks run on Informix?  Has
	anyone done it that could share their code with me?

	Thanks in advance

Kelly
kelly@ee.byu.edu




--
James Gritton - gritton@byu.edu - I disclaim
Newsgroups: comp.databases.informix
From: ptm@xact.demon.co.uk (Paul Thomas Mahoney)
Subject: Online Checkpoint Issues
Organization: X-Act Solutions Limited
Date: Thu, 3 Sep 1992 12:44:13 GMT

We run Online with about 200 users and I have some questions that I would
appreciate some comments to. The configuration is as follows:

 - The OS is SCO 3.2.2
 - We have 9 client machines (Dell 33MHz 486) each supporting 25 users
   running our application, written using ESQL/C.
 - These clients call across the net to the server (Dell 50MHz 486 with
   about 2GByte disk).
   
Thus about 200 connections over I-Star to the engine. All databases use
unbuffered logging and there is a 525MByte tape to do continuous backup.
Overnight a level 0 backup is done to DAT. Shared memory is about 14MByte.
Checkpoint interval is 3 mins. 

Now the problem:

Each checkpoint is taking 30-45 seconds to complete with about 3 megs of
log to be written to disk. As the checkpoint starts, all currently running
processes freeze. Then the disk activity takes place for 15-20 seconds and
then the user tasks wake up, some much more slowly that others.

Looking at the priorities of the sqlturbo processes on the server during
checkpoints we find that, during normal running, they are in the mid 20's
but by the end of the checkpoint their priorities have dropped (risen?) to
65-70. I suppose this accounts for their slowness in re-starting.

How can I reduce or preferably eliminate the pause in use?

Some solutions have been suggested:

1) Get a cacheing disk controller (and a UPS) to allow Online to think
   it has flushed the logs quicker.
2) Get a SparcServer.
3) Become a Monk so its somebody else's problem.

Any thoughts would be much appreciated.

-- 
Paul Mahoney, X-Act Solutions Limited
smail: 20 Shipley Lane, Cooden, Bexhill-on-Sea, East Sussex, TN39 3SR
email: ptm@xact.demon.co.uk ... pmahoney@cix.compulink.co.uk
phone: +44 424 3 6368