Linux-Misc Digest #441, Volume #26 Fri, 1 Dec 00 19:13:02 EST
Contents:
Re: problem with tcsh and bksp key (Sven Mascheck)
POS application? (ag)
/etc/fielsystems versus /proc/filesystems (Otto Wyss)
Re: ipchains error (Luke Vogel)
Dual Boot From Two Separate SCSI HD ("DVJ")
Re: vim: can't turn on syntax highlighting (Peter Moore)
Re: root password ([EMAIL PROTECTED])
Re: cron did not run, why? (Jean-David Beyer)
Re: Dual Boot From Two Separate SCSI HD (Jim McDonald)
Re: how to test a linux kernel ("Sylvain Drapeau")
Re: root password (Jean-David Beyer)
Re: Virtual mem exhaust problem? (Cliff Sarginson)
Re: root password ([EMAIL PROTECTED])
Re: Database in Redhat Linux ("Anthony W. Youngman")
Re: Database in Redhat Linux ("Anthony W. Youngman")
----------------------------------------------------------------------------
From: Sven Mascheck <[EMAIL PROTECTED]>
Subject: Re: problem with tcsh and bksp key
Date: 1 Dec 2000 23:16:02 +0100
Jean-Yves Simon <[EMAIL PROTECTED]> wrote:
> I have stty erase ^H in mt tcshrc file.
Generally you should better start with 'stty erase <ctrl-v><"erase"-key>'
- and you haven't explained your motivation.
> In this case, uder ftp or some other softs, the bksp doesn't work
> and echo ^?. But if type in the cli stty sane, I get the bksp to work.
Compare the output of 'stty -a' after that with the very beginning.
> Now, if I enter X, everything is bad again. I have found
> that if an X window, I type stty erase ^H , it works.
An X window or xterm in particular?
This also depends on your xmodmap (see xmodmap -pke in connection with xev).
> So, one thing I don't understand, is why when I have an
> stty erase ^H in my tcshrc , I can't see it anymore when
> I enter X.
console and X11 are completely different. You have to fix or adjust
it two times at worst.
Sven
------------------------------
From: ag <[EMAIL PROTECTED]>
Subject: POS application?
Reply-To: [EMAIL PROTECTED]
Date: Fri, 01 Dec 2000 22:25:02 GMT
Hi All,
I'm trying to find GPL POS software and am not having much luck. Any
ideas or suggestions where I might look? Thanks.
If this post is off-topic for this NG, I apologise.
AG
------------------------------
From: [EMAIL PROTECTED] (Otto Wyss)
Subject: /etc/fielsystems versus /proc/filesystems
Date: Fri, 1 Dec 2000 23:37:42 +0100
Since I rather like floppies mounted as vfat instead of msdos (using
auto in fstab), I consider creating a /etc/filesystems. Or is there a
way to change the order in /proc/filesystems to get the same effect?
O. Wyss
------------------------------
From: Luke Vogel <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
Crossposted-To: alt.os.linux,comp.os.linux.networking,comp.os.linux.security
Subject: Re: ipchains error
Date: Sat, 02 Dec 2000 08:37:38 +1000
Marvin Greenberg wrote:
>
> "Luke Vogel" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]...
> > Darren Welson wrote:
> > >
> >
> > Most firwall scripts are fairly long, with several references to the
> > ipchains command. If the error is caused by syntax errors, simply place
> > a few "breakpoints" in strategic places and you can then isolate where
> > in the script the errors are occuring.
> >
> Or add "set -x" at the top of the script (sh,bash,ksh).
That'll do it too ...
I like to put lines like:
echo -n "Establishing HTTP Server/Client Access ... "
...
(ipchains rules go here ...)
...
echo "Done."
etc
That way I know imediately what the script is doing and where it fails
:)
--
Regards
Luke
PLEASE NOTE: Spamgard (tm) installed.
----
When the only tool you own is a hammer,
all problems begin to resemble nails.
----
http://www.bell-bird.com.au
mailto:[EMAIL PROTECTED]
----
------------------------------
From: "DVJ" <[EMAIL PROTECTED]>
Subject: Dual Boot From Two Separate SCSI HD
Date: Fri, 1 Dec 2000 16:43:17 -0600
Hello everyone:
I have a PC with an SCSI Adaptec 294xx adapter, and one NTFS formatted disk
running WinNT4.0. I would like to have dual-boot machine, but since I have a
lot of data and applications on this disk, I would not like to experiment
with reconfiguring the partitions, etc. Plus, I don't have a tape to fully
backup the drive, so...
My idea is of adding a new SCSI disk instead, and selectively booting from
either of the disks. The question is:
Is it possible to do that with the present configuration, and if yes, what
utilities would I have to use to facilitate selection of boot disks at
start-up time?
Any help will be greatly appreciated,
D.V. Josephson
------------------------------
From: [EMAIL PROTECTED] (Peter Moore)
Subject: Re: vim: can't turn on syntax highlighting
Date: 1 Dec 2000 22:58:12 GMT
>On Fri, 01 Dec 2000 03:27:48 GMT,
> [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>>start vi using vim
>>or alias vi='vim'
>Explanation: On Redhat /bin/vi is a vim version compiled without
>bells and whistels. The full vim is installed /usr/bin/vim, and
>you need to install all 3 vim related rpm packages.
Thanks. This seems like just one more little reason for me to finally switch
my home machine over to Debian. I've been using it at work, and things just
seem to work with less mess -- especially software installs. It's always
good to know your way around a few distros though, quirks and all...
-Peter
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: root password
Date: Fri, 01 Dec 2000 23:03:55 GMT
In article <[EMAIL PROTECTED]>,
Jean-David Beyer <[EMAIL PROTECTED]> wrote:
> Bob Tennent wrote:
> >
> > On Fri, 01 Dec 2000 19:27:14 GMT, [EMAIL PROTECTED] wrote:
> > >Help....I am running redhat 6.2 i386. I was hacked and my root
password
> > >was changed. I was able to boot to run level 1 and change the
root
> > >password to something else. Now I can login as root using the
password
> > >I changed it to. When I log directly into root it seems to work
no
> > >problem and allows me to do all the normal things root can do.
> > >However if I do not initially login as root, I can not su to root,
using
> > >that password. It says incorrect password. This happens whether
I
> > >su, su -, or su root. Very wierd. I am stumped?
> >
> > Quite likely the su program has been replaced by a password sniffer.
> > I hope you have your data backed up
>
> Backed up from just before the cracker cracked your system, right?
> Because afterwards, the data cannot be trusted. Juvenile crackers my
> simply delete files, but the real nasties make just minor changes here
> and there in your data.
>
> Another reason not to back up your data to another hard drive: the
> cracker can screw up both, so you have nowhere from where to
> restore... .
>
> > because the best thing to do now
> > is to wipe your installation and re-install. And this time, do the
> > security updates and install portsentry before re-connecting to the
> > network.
> >
> > Bob T.
>
> --
> .~. Jean-David Beyer Registered Linux User 85642.
> /V\ Registered Machine 73926.
> /( )\ Shrewsbury, New Jersey
> ^^-^^ 4:20pm up 5 days, 23:47, 2 users, load average: 2.07, 2.16, 2.13
>
thanks for the replies. it took me quite a long long time to set this
system up how i want. And I would rather not wipe my entire syste, are
there any other recommended plans of attack?
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: Jean-David Beyer <[EMAIL PROTECTED]>
Subject: Re: cron did not run, why?
Date: Fri, 01 Dec 2000 18:19:14 -0500
Russ wrote:
>
> One possibility is that cron did not immediately read the new crontab. After
> a crontab file is edited, cron needs to re-read the file in order to be
> aware of any changes. This can be done either by stopping and re-starting
> cron, or by using the "crontab -e" approach to modifying your crontab.
I do not think you need to bother (man cron):
Cron searches /var/spool/cron for crontab files which are
named after accounts in /etc/passwd; crontabs found are
loaded into memory. Cron also searches for /etc/crontab
and the files in the /etc/cron.d/ directory, which are in
a different format (see crontab(5)). Cron then wakes up
every minute, examining all stored crontabs, checking each
command to see if it should be run in the current minute.
When executing commands, any output is mailed to the owner
of the crontab (or to the user named in the MAILTO
environment
variable in the crontab, if such exists).
Additionally, cron checks each minute to see if its spool
directory's modtime (or the modtime on /etc/crontab) has
changed, and if it has, cron will then examine the modtime
on all crontabs and reload those which have changed. Thus
cron need not be restarted whenever a crontab file is modified.
Note that the Crontab(1) command updates the modtime of the
spool directory whenever it changes a crontab.
>
> It could also be that the CPU was very busy and it just took a while before
> the drive activity was noticeable.
>
> just my $.02
> Russ
>
> <[EMAIL PROTECTED]> wrote in message news:908jcb$cr7$[EMAIL PROTECTED]...
> > I wanted to make a simple backup routine to back up nightly. My crontab
> > file looks like:
> >
> > 45 23 * * * /root/backup_script
> >
> > Of course, this was a test on a local system with no other users. I
> > plan to put a similar script into /usr/local/bin (I don't mind regular
> > users running the backup script). I used "crontab crontab" and crontab -
> > l looks fine. It was actually 23:35 when I set it, so it was supposed
> > to run in ten minutes. I logged out of root and left it alone. When I
> > came back (0:05), the backups tars were not to be found. But after
> > searching for it (not in root), I heard the hard drive move and to my
> > surprise, the backups were made. So I'm wondering why my cron command
> > didn't run at the specified time. I ran "date" to make sure that my
> > linux box was set properly.
> >
> > Since I ran it as root, it certainly doesn't have to wait until root
> > logged in. Did my computer go into suspend mode or something? If so,
> > how am I supposed to prevent it from suspending on real machines? Or
> > did it need time to register the new cron file (since it eventually ran
> > the script)? Any help...even guesses...will help.
> >
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey
^^-^^ 6:15pm up 6 days, 1:42, 2 users, load average: 2.35, 2.14, 2.09
------------------------------
From: Jim McDonald <[EMAIL PROTECTED]>
Subject: Re: Dual Boot From Two Separate SCSI HD
Date: Fri, 01 Dec 2000 15:14:48 -0800
DVJ wrote:
>
> My idea is of adding a new SCSI disk instead, and selectively booting from
> either of the disks. The question is:
>
> Is it possible to do that with the present configuration, and if yes, what
> utilities would I have to use to facilitate selection of boot disks at
> start-up time?
>
No problem at all. Just did it myself.
The utility is called "Lilo".
--
Jim McDonald
------------------------------
From: "Sylvain Drapeau" <[EMAIL PROTECTED]>
Subject: Re: how to test a linux kernel
Date: Fri, 1 Dec 2000 17:08:28 -0500
I can't give you the exact steps but if you could install it on a boot
floppy (I think it's 'make bzdisk')... you boot on the floppy and try it, if
it doesn't work, you remove the floppy and boot your usual kernel.
Reading the Kernel HowTo might help.
http://www.linuxdoc.org/HOWTO/Kernel-HOWTO.html
~~~~~~~~~~~~~~~~~~~~~~~~
Sylvain Drapeau
Solutions Informatiques SIGMA Inc.
tél: (418)851-2943 x104
(418)851-4254
fax: (418)851-4580
[EMAIL PROTECTED]
www.sigma-techno.com
"news" <[EMAIL PROTECTED]> a écrit dans le message news:
907odp$g57$[EMAIL PROTECTED]
> I received a reducd linux kernel version, how could I test it? If you
know,
> please list the steps, thanks.
>
>
------------------------------
From: Jean-David Beyer <[EMAIL PROTECTED]>
Subject: Re: root password
Date: Fri, 01 Dec 2000 18:24:32 -0500
[EMAIL PROTECTED] wrote:
>
> In article <[EMAIL PROTECTED]>,
> Jean-David Beyer <[EMAIL PROTECTED]> wrote:
> > Bob Tennent wrote:
> > >
> > > On Fri, 01 Dec 2000 19:27:14 GMT, [EMAIL PROTECTED] wrote:
> > > >Help....I am running redhat 6.2 i386. I was hacked and my root
> password
> > > >was changed. I was able to boot to run level 1 and change the
> root
> > > >password to something else. Now I can login as root using the
> password
> > > >I changed it to. When I log directly into root it seems to work
> no
> > > >problem and allows me to do all the normal things root can do.
> > > >However if I do not initially login as root, I can not su to root,
> using
> > > >that password. It says incorrect password. This happens whether
> I
> > > >su, su -, or su root. Very wierd. I am stumped?
> > >
> > > Quite likely the su program has been replaced by a password sniffer.
> > > I hope you have your data backed up
> >
> > Backed up from just before the cracker cracked your system, right?
> > Because afterwards, the data cannot be trusted. Juvenile crackers my
> > simply delete files, but the real nasties make just minor changes here
> > and there in your data.
> >
> > Another reason not to back up your data to another hard drive: the
> > cracker can screw up both, so you have nowhere from where to
> > restore... .
> >
> > > because the best thing to do now
> > > is to wipe your installation and re-install. And this time, do the
> > > security updates and install portsentry before re-connecting to the
> > > network.
> > >
> > > Bob T.
>
> thanks for the replies. it took me quite a long long time to set this
> system up how i want. And I would rather not wipe my entire syste, are
> there any other recommended plans of attack?
Load new versions of your backup utilities from CD-ROM or the
distribution floppy and do a byte-for-byte compare of what is on your
system with your most recent backup tape made before the cracker got
it. Only works, of course, if you do frequent complete system backups.
Why not just restore your system from your most recent backup made
before the cracker got in? But be sure you restore clean copies of
things like your kernel, cpio, etc., (whatever you use) from your
distribution media. Because you cannot really even trust your kernel
anymore. If the stuff on the distribution media is out of date, at
least it will be relatively secure. You can restore the more
up-to-date versions from your complete system backup. Then you might
dare get onto the Internet again and download all the latest security
enhancements for your distribution.
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey
^^-^^ 6:15pm up 6 days, 1:42, 2 users, load average: 2.35, 2.14, 2.09
------------------------------
From: Cliff Sarginson <[EMAIL PROTECTED]>
Crossposted-To: comp.os.linux.setup
Subject: Re: Virtual mem exhaust problem?
Date: Thu, 30 Nov 2000 03:05:11 +0100
Dances With Crows posited:
> On Wed, 29 Nov 2000 19:32:28 GMT, ne... wrote:
> >On Nov 29, 2000 at 13:44, Chet Vora eloquently wrote:
> >
> >>Mem 30M 29M .7M
> >>Swap: 68M 3.5M 64M
> >>Is a 68M swap size
> >>right or will I be benefitted by increasing it ?
> >/boot is when the kernel is stored. This is not the swap partition.
The swap device will not be seen as a mounted file system because it isn;t
one.. to view the swap devices/files use ...
swapon -s
> >
> >>THis is a 32M RAM,180 MHz Pentium machine. Would also appreciate
> >>feedback about how to resolve the "Virtual Mem exhaust" problem. I'm
> >>trying to compile a protocol stack which in turn uses flex and yacc. Any
> >>pointers will be welcome.
> >Due to the amount of ram you have, it would seem you need more swap.
> >The swap initially allocated would have been ok if you weren't
> >compiling stuff. I
I agree with this analysis..compilations lurrv memory...
t more seems you need more hardware. If you have
> >unformatted space on /dev/hda, I would format this for swap. Else, if
> >you have a spare harddrive, this could be used for swap also.
>
> Spare harddrive? Heck with that; if you have *any* spare space on the
> root partition, you can get more swap space. Like so: (must be done as
> root, natch.)
>
> dd if=/dev/zero of=/swapfile bs=1M count=64
> sync
> sync
> mkswap /swapfile
> swapon /swapfile
>
> Add /swapfile to /etc/fstab to enable the extra swap space at boot time.
> HTH,
>
Adding a new spaw device as in the first suggestion is a *much* better idea.
Swap files will be very very slow compared to swap devices 'cos of the way
they are accessed by the kernel. Since you are doomed to swapping might
as well do it properly ! Swapfiles are a hack for emergency use only...
Cliff
--
no NAUGHTYSPAM if you email me :)
------------------------------
From: [EMAIL PROTECTED]
Subject: Re: root password
Date: Fri, 01 Dec 2000 23:19:24 GMT
In article <[EMAIL PROTECTED]>,
Jean-David Beyer <[EMAIL PROTECTED]> wrote:
> Bob Tennent wrote:
> >
> > On Fri, 01 Dec 2000 19:27:14 GMT, [EMAIL PROTECTED] wrote:
> > >Help....I am running redhat 6.2 i386. I was hacked and my root
password
> > >was changed. I was able to boot to run level 1 and change the
root
> > >password to something else. Now I can login as root using the
password
> > >I changed it to. When I log directly into root it seems to work
no
> > >problem and allows me to do all the normal things root can do.
> > >However if I do not initially login as root, I can not su to root,
using
> > >that password. It says incorrect password. This happens whether
I
> > >su, su -, or su root. Very wierd. I am stumped?
> >
> > Quite likely the su program has been replaced by a password sniffer.
> > I hope you have your data backed up
>
> Backed up from just before the cracker cracked your system, right?
> Because afterwards, the data cannot be trusted. Juvenile crackers my
> simply delete files, but the real nasties make just minor changes here
> and there in your data.
>
> Another reason not to back up your data to another hard drive: the
> cracker can screw up both, so you have nowhere from where to
> restore... .
>
> > because the best thing to do now
> > is to wipe your installation and re-install. And this time, do the
> > security updates and install portsentry before re-connecting to the
> > network.
> >
> > Bob T.
>
> --
> .~. Jean-David Beyer Registered Linux User 85642.
> /V\ Registered Machine 73926.
> /( )\ Shrewsbury, New Jersey
> ^^-^^ 4:20pm up 5 days, 23:47, 2 users, load average: 2.07, 2.16, 2.13
>
thanks for the replies. it took me quite a long long time to set this
system up how i want. And I would rather not wipe my entire system, are
there any other recommended alternatives? Is there anyway to tell if
the data is safe or not?
Sent via Deja.com http://www.deja.com/
Before you buy.
------------------------------
From: "Anthony W. Youngman" <[EMAIL PROTECTED]>
Crossposted-To:
comp.os.linux.development.apps,comp.os.linux.development.system,comp.os.linux.apps,comp.lang.java.databases,comp.databases.informix,comp.databases.oracle.server,comp.databases.sybase,comp.databases.pick,comp.databases.ibm-db2,comp.databases.oracle.misc
Subject: Re: Database in Redhat Linux
Date: Fri, 1 Dec 2000 21:02:59 +0000
Reply-To: "Anthony W. Youngman" <[EMAIL PROTECTED]>
In article <904rq3$54b$[EMAIL PROTECTED]>, Victor Wagner
<[EMAIL PROTECTED]> writes
>In comp.os.linux.misc Anthony W. Youngman <[EMAIL PROTECTED]> wrote:
>: In article <8vmgld$om4$[EMAIL PROTECTED]>, Victor Wagner
>: <[EMAIL PROTECTED]> writes
>:>In comp.os.linux.misc Freelancer <[EMAIL PROTECTED]> wrote:
>:>: I need decide which database going to run for Redhat Linux.
>:>: I know MySQL is the most popular one in Linux world. I need
>:>: you help me to fill out the blank and hole (?) in table below.
>:>
>:>Its a pity for Linux World, that most hype is done by people who don't
>:>know what real database is. So they promote mySQL which is no more than
>:>fast flat-file search engine with SQL-like syntax.
>
>: And it's a real pity that there are so many people who think that the
>: only valid type of database is a SQL database.
>
>Sincerely, I never seen any other kind of database which is usable
>without writing special program for any query. SQL is only practical
>solution've seen, which allows you to type queries in interactively.
>There is also QBE, but it doesn't count, becouse it is
>a) relational
>b) if fully implementted is functionally equivalent to SQL.
>
Ask an END USER to run a query over four entities. Oh, by the way,
there's a many-to-many relationship in there somewhere...
Dead easy for us, unless you assume the user is an idiot and stick a GUI
in the way - unfortunately that's usually a self-fulfilling prophecy :-(
>
>Restriction which mySQL places on the programmers are worst of all - they
>causes them to PROGRAM, instead of to DESIGN.
>
I don't know mySQL that well, but you need some programming for
anything. If you mean triggers, data integrity etc, I gather mySQL was
designed for fast extraction, and it sounds like you're using the wrong
tool for the job...
>
>
>:>
>:>But database is much more than just search engine. It also should ensure
>:>integrity of data both by enforcing some conditions of them (i.e.
>:>foreign keys and triggers) and by rolling failed transactio back to
>:>consistent state.
>
>: And to me, a database is a complete environment, aka AS/400, Pick, etc.
>: A SQL back-end is to databases what the rear legs are to pantomime
>: donkey - it can stand on its own but is useless without the other half.
>
>SQL + storage manager behind them. Nothing more. Even OS is not always
>neccessary.
>May be FORTRAN
>preprocessor. Clients should be written on normal using
>jdbc, odbc, dbi or some other kind of standartized interface.
>
>Of course good interactive shell is good, but I always have dbish.
>
A good interactive shell makes life easy...
>:>
>:>So, only free database is PostgreSQL. But PostgreSQL start to
>:>resemble real database only since 7.0 version, becouse before there was
>:>no foreign keys. I would consider that it IS a database, not RESEMBLES
>:>one only when it begin to support outer joins and binary large objects.
>:>Both are scheduled for 7.1.
>:>
>: I think you mean the only free *relational* database - which is not the
>: same thing at all. There are much better databases out there. While I
>
>Please name _free_ non-relational database which is comparable with
>commercial ones. As far as I know, most free non-relational things are
>compared with say Adabas, like mySQL to Oracle or worse.
I don't know of any _free_ ones that are currently usable. I'm working
on MaVerick...
>
>: would strongly suggest that all database programmers should know
>: relational theory (it helps design immensely), there are a load of far
>: better databases out there. SQL and relational databases put theoretical
>: purity above practicality and functionality, which is why Oracle is such
>: a beast - I could probably write programs that run faster, do more, and
>: handle larger datasets, and all on a system half the size! just because
>: I don't believe "relational is best".
>
>Guys who wrote mySQL think same way. Unfortunately, they was wrong.
>Becouse there is nothing more practical then good theory.
>
>Theoretical purity gives flexibility, scalability and tunability.
>This is why people don't write on CODASIL anymore.
>
Rules are for the guidance of wise men, and the obedience of fools. The
real world is not amenable to forcing into a relational mould. For some
things it works fine, but trying to force non-relational data into a
relational straitjacket can (will?) make life difficult later on. Why
are people now throwing so much effort at object databases? Try running
a data warehouse on a relational db - a big warehouse will bring a Cray
to its knees...
That's why I said I could blow Oracle into a cocked hat - I take their
strengths, add them to mine, and dodge their straitjacket :-)
--
Anthony W. Youngman <[EMAIL PROTECTED]>
'Yings, yow graley yin! Suz ae rikt dheu,' said the blue man, taking the
thimble. 'What *is* he?' said Magrat. 'They're gnomes,' said Nanny. The man
lowered the thimble. 'Pictsies!' Carpe Jugulum, Terry Pratchett 1998
Visit the MaVerick web-site - <http://www.maverick-dbms.org> Open Source Pick
------------------------------
From: "Anthony W. Youngman" <[EMAIL PROTECTED]>
Crossposted-To: comp.databases.pick
Subject: Re: Database in Redhat Linux
Date: Fri, 1 Dec 2000 21:16:51 +0000
Reply-To: "Anthony W. Youngman" <[EMAIL PROTECTED]>
In article <[EMAIL PROTECTED]>, Jean-David Beyer
<[EMAIL PROTECTED]> writes
>Victor Wagner wrote (in part):
>
>> : would strongly suggest that all database programmers should know
>> : relational theory (it helps design immensely), there are a load of far
>> : better databases out there. SQL and relational databases put theoretical
>> : purity above practicality and functionality, which is why Oracle is such
>> : a beast - I could probably write programs that run faster, do more, and
>> : handle larger datasets, and all on a system half the size! just because
>> : I don't believe "relational is best".
>>
>> Guys who wrote mySQL think same way. Unfortunately, they was wrong.
>
>Chris Date, on of the best experts on Database Management Systems put
>a lot of effort in describing hierarchical database management systems
>such as IBM's IMS/DB and network-model databases systems (I forget the
>right name for these) in the first and second editions of his classic
>book, "An Introduction To Database Systems". He did this because such
>systems were in common use because their implementations were more
>efficient. He no longer treats anything except the relational model
>(including object-oriented relational model) because their efficiency
>is now as good for well executed rdbms as any other model.
Which is why I always DESIGN using relational theory. But when I
implement, I like to be able to avoid its constraints. Why force data
into a relational straightjacket when it's not relational in nature?
>
>You can always hear arguments that some other way (than using a dbms,
>especially an rdbms) is more efficient of something, usually cpu
>resources, memory resources, disk space resources... . And, for any
>static application, the argument would be correct. You could do it all
>with ordinary flat files. But that is missing the point: there are
>NEVER such static applications. And as soon as some change in
>requirements comes along, only the relational model (typically with a
>SQL API or user interface) will have the flexibility to handle this in
>a timely way. The cost of the programmers and database administrators
>and delays always exceeds the cost of the other resources.
What's a database administrator? Okay, I'm being facetious, but they're
pretty much unknown in the Pick world - there's no need for them. As for
programmers - well, I'm expecting the size of my department to DOUBLE
(or more) when we move over to SQL - and the service our users will get
will go down at the same time :-( Damn PHB's. For a given turnover, the
company using Pick as its database will typically be spending half the
amount a SQL-based company will be on its database. And IT will probably
be providing a better service, too (that's if there is an IT department
- it's usually much smaller).
And delays? User wants an ad-hoc query over four or five tables? How
long would it take a SQL programmer to extract the data? We expect our
users to do it for themselves - it's pretty easy.
>
>The arguments against rdbms are the same as the arguments that were
>made in the 1950s and 1960s against higher level languages such as
>COBOL, FORTRAN, JOVIAL, and all the others. They were wrong for the
>same reasons: programming and coding time cost more than the hardware
>needed to compensate for the greater hardware demand. Even back then,
>programming cost was too high compared to now. And now, hardware is at
>least 1000x cheaper than it was then.
>
>> Becouse there is nothing more practical then good theory.
>>
>> Theoretical purity gives flexibility, scalability and tunability.
>
>Also PORTABILITY, very important sometimes.
>
Portability is important. But it's a crying shame when PHBs move from a
portable, flexible system (with several competitors selling
approximately the same thing, so no vendor lock-in) to something that's
more expensive, less flexible, far more labour-intensive, just because
they're led up the garden path by advertising and hype.
--
Anthony W. Youngman - wol at thewolery dot demon dot co dot uk
Witches are curious by definition and inquisitive by nature. She moved in. "Let
me through. I'm a nosey person.", she said, employing both elbows.
Maskerade : (c) 1995 Terry Pratchett
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