Re: [slang-users] SLAG update and information.

[Ben Duncan <ben@xxxxxxxxxxxxxxxxxx>]

Ok, first off, If in proceeding conversations, if i get a might trite,
forgive me, I am not trying to be. I AM enjoying these discussions
immensely. I am a Applications programmer by trade, not a System Programmer.

Anyway, yes, I have 10 months to get this thing done now. I DO have the Appgen
stuff as my model basis, as well as a whole slew of old COBOL programs and
source to them. I actually converted a old MCBA COBOL program (Version 2.0) that was
dated back in the 1980's and used a "screen" driver in about 10 minutes to SLAG.
It was a simple Customer File Maintenance screen. I actually have a bunch
of FoxPro applications as well and the source to them.

SOP in the AR OPEN file discussion, is to have the all the
AR-OPEN records in one file. Usually in Inventory, you have a Item master
and then a Warehouse Item File, and in some more sophisticated systems
a "BIN" file, which forms a one to many to many link. Hence Multi values
work really well here. So there are and will be all sorts of variations.

The idea is to follow what I already have and I know how it works. Ditto for
any Applications Programmers whom pick up and go with SLAG.

In duplicate key reference's , in the old VSAM/ISAM methods, and using a
Customer Master as a reference here, you would have a PRIMARY key of
Customer number, but could have "Customer Name" as a secondary index. SO
in lookups, you would do a START on Customer NAME key and return a screen
full of customers in a pick list.

Now Appgen's dbm was a key/data block mode type file manager. To do a
lookup, it used a secondary file that was built using "whatever" you
attribute you specified, then put the real key in a multi value list.
It was not a TRUE multi value like PICK, but used a list separator of
"xFF" between each of the the multi value strings.
Field delimiters were NULLS between each and every field. It is almost
a 4NF overlayed on top of a key/data dbm engine.

From what I can deduce, it actual
created a in memory linked list when you read the datafile.
It suffered from SOME bad corruption's from time to time.
Record locking seems to be controlled by a "row" header that got a
byte set that flagged the record as locked. Each record in the file
always has a 36 byte header in it.

Another data file manager I am looking at is the VBISAM out on
soruceforge.net. It is an FOSS ISAM replacement for C-ISAM.

Any suggestions or comments on that one?

As always, you ARE appreciated and thanks for the time and effort
in responding to me !!!!

Paul Boekholt wrote:
> On Sun, 07 Aug 2005 13:10:50 -0500, Ben Duncan <ben@xxxxxxxxxxxxxxxxxx> said:
<SNIP>

--
Ben Duncan   - VersAccounting Software LLC 336 Elton Road  Jackson MS, 39212
"Never attribute to malice, that which can be adequately explained by stupidity"
       - Hanlon's Razor


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