MVISAM Advice solicitation

[Mike Reinehr]

On Monday 30 October 2006 08:01, Ben Duncan wrote:
> Ok, After having earned a living for the past 2 or 3 months
> and with a little money socked away / due in (yeah, I know
> don't count your BENJAMINS before they hatch), I am thinking
> about getting back on my SLAG/MVISAM project ,due to the recent
> thread's here about FOSS Accounting systems.
>
> Ok, here is the state of it:
>
> I can make it look 3D and Graphical. I can use 256 Color xterm
> (Yeah, I have been experimenting with it - nice !!) and the
> GTK+ for S-lang. The intrensic's are designed to have those
> "common" controls - radio buttons, select lists, standard
> buttons, and the like, most of them are implemented and most
> work - Both in Text mode and eventually GUI (using GTK+).
> The premise is simply - simply call the function you want and
> the underlying mechanics handle it all, whether a true GUI or
> text mode.
>
> Ok, now back to the Database end. The MVISAM is designed to be
> a simple, multi user, multi key, multi value record manager that
> supports ROW locking. I was at the place where all the functions to
> handle key manipulation is done. The very same functions can be used
> to handle Multi values - so that is essential done as well.
> Where the fork in the road came to, was to decide to have both
> key nodes and data node reside in the same file OR have 2
> different files with one being key node and the other being data nodes.
> Now, I have just complete an Acucobol conversion and notices that
> AcuCobol's VISION ISAM file manager has gone for a single file, to
> a dual set up (key / data files). I have also noticed some of the
> other ISAM file managers (commercial ones) have done the same.
> Also, MySQL base uses the 2 file method, while the INNODB add on,
> puts it all in one file.
>
> Question is, and the advice needed is, do I use 2 files like the rest
> of the world, or just keep it in one file?
> Pro's? Con's?
>
> REALLY Need input form those whom prolly more experienced at these
> kind of things.

I'm sure I'm less experienced than you but that won't stop me from having an 
opinion! ;-)

I confronted the same question during my last Southware installation a year 
ago. As you point out, the Acucobol-GT default now is Vision Version 4, which 
results in a dual file structure. From my standpoint I haven't really seen 
any practical difference between the two, but Southware decided to stay with 
Vision Version 3 and a single file structure. I can't say whether they 
decided this due to performance reasons or just to keep life a little 
simpler. Since performance wasn't a problem for me, I decided to stay with 
VV3 and half the number of files in each directory.

Cheers,

cmr
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