Re: In an RDBMS, what does "Data" mean?

Notes embedded.

> "mAsterdam" <mAsterdam_at_vrijdag.org> wrote...
>
>> Anthony W. Youngman wrote...
>>
> > So if I put my data into an MV database I can access it as if it were in
> > an RDBMS. However, the converse is not true.
>
> It would be very interesting to know - in some detail -
> what kind of data gives difficulties in putting stuff
> from a RDBMS into a MV database.
> This maybe somewhat awkward in this newsgroup, because some
> will be just waiting to say: See? You *can* express proposition_set(x)
> in a RDBMS, and you *can't* in MV, therefore MV is better.
> More is not a priori better.
>
> But I trust you can stand that reaction. Could you give some examples?

Here's an A/P invoice record. The view is vertical, not horizontal. The numbers on the left indicate the field location# in the physical string on disk. The unnumbered value is the record key.

    340*VR3-2
001 480
002 13279
003 13210
004 74*578
005 LOAN PAYMENT, 3/2004
006 -297645
007 0
008 -297645
009 5170]3370]5170]3370
010 -101261]-196384]0]0
011 200404
012 200404
013
014
015 AUTO
016
017 74

The disk storage would look like:

^^340*VR3-2^480^13279^12114^74*578^LOAN PAYMENT, 3/2004^-297645^0^-297645^5170]3370]5170]3370^-101261]-196384]0]0^200404^2004 04^^^AUTO^^74 The contents of field#s 009 & 010 are the G/L acct#s assigned this invoice and the "associated" G/L amounts allocated to each G/L acct#. The last two "values" of field# 10 are zero (0), but could just as easily be nothing so the field could look like:

010 -101261]-196384]]

There are no data types in this record. Field#s 002 & 003 are dates where each date is the number of days past 31 Dec 1967 (kind of like unix's # of seconds past midnight on 01 January 1970. The values of field#s 006, 008, and 010 are monetary values with the decimal stripped, so the value 25 would indicate $.25 (or .25 of whatever denomination used).

To load a valid date into a Pick-like dbms (mvDbms) a conversion needs to be done similar to what is done for Unix. The same is true for money amounts. However, extraction is very easy so that:

::LIST APOPEN '340*VR3-2' INVDATE DUEDATE ACCTS AMTS Page 1 APOPEN

APOPEN.... INV-DATE DUE-DATE ACCT. ACCT/AMTS....

340*VR3-2  03-01-01 05-09-04 5170      1,012.61-
                             3370      1,963.84-
                             5170          0.00
                             3370          0.00

[405] 1 items listed out of 1 items.

or the relational way:

::LIST APOPEN '340*VR3-2' BY-EXP ACCTS INVDATE DUEDATE ACCTS AMTS Page 1 APOPEN

APOPEN.... INV-DATE DUE-DATE ACCT. ACCT/AMTS....

340*VR3-2  03-01-01 05-09-04 3370      1,963.84-
340*VR3-2  03-01-01 05-09-04 3370          0.00
340*VR3-2  03-01-01 05-09-04 5170      1,012.61-
340*VR3-2  03-01-01 05-09-04 5170          0.00

[405] 4 items listed out of 1 items.

(if this appears in a proportional font simply cut & paste to notepad)

I hope this answered your question. :-)

Bill Received on Fri Jun 11 2004 - 01:40:40 CEST