[Info-vax] Databases versus RMS

[Paul Sture]

On Wed, 18 Apr 2012 08:32:55 -0500, Bob Koehler wrote:

> In article <4f8dbbf4$0$24585$c3e8da3$e408f015 at news.astraweb.com>, JF
> Mezei <jfmezei.spamnot at vaxination.ca> writes:
>> 
>> Are database engines so fragile that a power failure will truly wreak
>> havok on a database requiring time consuming work and debugging ?
> 
>    From time to time, things that should work, like databases, or
>    filesystems, don't.  Generally vendors will fix things real quick. I
>    once spec'd IBM AIX in part because I assumed that IBM would provide
>    a bug free filesystem.  Boy was I suprized when I had to manually run
>    fsck after every power outage.  I was not suprized when the next
>    minor version release fixed it.

fsck on Linux will also run every n restarts.  On my first Linux system a 
dozen years ago, n was something like 6.  Since it was a dual boot system 
I could easily get there several times a week.  It took so long with the 
hardware I was using that it was time to put the kettle on. And possibly 
make a sandwich too.

>    "database" could also be a collection of data, without an actual
>    DBMS.
> 
>    But it's easy to buy a DBMS that does work, and not uses it
>    correctly.

I had a clear demonstration of that with some trial personal accounting 
software for Macs, which was so slow as to be unusable.  I know I wasn't 
running it on the latest and greatest hardware, but that same machine was 
quite capable of running industrial strength commercial accounting 
packages.

It turned out that this software was using PostgreSQL, and provided dumps 
in SQL format (plus marks for that).  OTOH inspection of the SQL revealed 
countless indexes which only ever contained one of 2 or 3 values.

Sorry, but I learn that indexes with only 2 values such as "M" and "F" 
were bad news back in RMS days.  I'm pretty sure the RMS documentation 
included that as an example of things not to do.

-- 
Paul Sture