Powerhouse 4GL RDBMS Question - Subitems
Deskin, Bob
Bob.Deskin@Cognos.COM
Thu, 25 Sep 2003 11:47:42 -0400
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That is correct.
With IMAGE, we read the schema into the dictionary and then allow what are
effectively overlays or substructures. With IMAGE, we read and write the
entire record.
With relational, we do not read the schema into the dictionary. Rather we
access the schema from QDESIGN, QUIZ, or QTP when we are parsing QDESIGN,
QUIZ, or QTP source code. With relational, we do not read and write the
entire row. Rather we read and write the columns that are used in the
screen, report, or run. This is the recommended approach for relational
databases.
Note that, while in common usage, substructuring is not really a normalized
approach to data and relational databases work best with normalized data.
This is an issue that must be dealt with when migrating PowerHouse from
IMAGE to relational.
Bob Deskin
Product Manager, Application Development Tools, Cognos Inc.
bob.deskin@cognos.com (613) 738-1338 ext 7268 FAX: (613) 727-1178
3755 Riverside Drive P.O. Box 9707 Stn. T, Ottawa ON K1G 4K9 CANADA
-----Original Message-----
From: Charles Finley [mailto:cfinley@xformix.com]
Sent: Thursday, September 25, 2003 10:34 AM
To: powerh-l@lists.swau.edu
Subject: Powerhouse 4GL RDBMS Question - Subitems
With IMAGE DB you can define Subitems in Powerhouse which is nothing else as
using one single field out of the database and defining a data structure
within Powerhouse for this single DB field using the PHD (Powerhouse
Dictonary).
Example:
Field in IMAGE DB: X CHAR(10)
Subitems in Powerhouse using field X of IMAGE DB:
subitem1 CHAR(3)
subitem2 CHAR(3)
subitem3 CHAR(4)
We are speaking with someone who has told us that they have tried to do
this with a relational DB and learned that is under the impression that
Powerhouse does not support this ability to overlay fields for a
relational DB, only for IMAGE DB. The client went on to say that you cannot
define Subitems in the Powerhouse Dictonary for a relational DB.
Can someone confirm this?
Charles Finley
Transformix Computer Corporation
(760)-439-3146
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<TITLE>RE: Powerhouse 4GL RDBMS Question - Subitems</TITLE>
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<P><FONT SIZE=3D2>That is correct.</FONT>
</P>
<P><FONT SIZE=3D2>With IMAGE, we read the schema into the dictionary =
and then allow what are effectively overlays or substructures. With =
IMAGE, we read and write the entire record.</FONT></P>
<P><FONT SIZE=3D2>With relational, we do not read the schema into the =
dictionary. Rather we access the schema from QDESIGN, QUIZ, or QTP when =
we are parsing QDESIGN, QUIZ, or QTP source code. With relational, we =
do not read and write the entire row. Rather we read and write the =
columns that are used in the screen, report, or run. This is the =
recommended approach for relational databases.</FONT></P>
<P><FONT SIZE=3D2>Note that, while in common usage, substructuring is =
not really a normalized approach to data and relational databases work =
best with normalized data.</FONT></P>
<P><FONT SIZE=3D2>This is an issue that must be dealt with when =
migrating PowerHouse from IMAGE to relational.</FONT>
</P>
<P><FONT SIZE=3D2>Bob =
Deskin =
</FONT>
<BR><FONT SIZE=3D2>Product Manager, Application Development Tools, =
Cognos Inc.</FONT>
<BR><FONT SIZE=3D2>bob.deskin@cognos.com (613) 738-1338 ext 7268 FAX: =
(613) 727-1178</FONT>
<BR><FONT SIZE=3D2>3755 Riverside Drive P.O. Box 9707 Stn. T, Ottawa ON =
K1G 4K9 CANADA</FONT>
</P>
<P><FONT SIZE=3D2>-----Original Message-----</FONT>
<BR><FONT SIZE=3D2>From: Charles Finley [<A =
HREF=3D"mailto:cfinley@xformix.com">mailto:cfinley@xformix.com</A>]</FON=
T>
<BR><FONT SIZE=3D2>Sent: Thursday, September 25, 2003 10:34 AM</FONT>
<BR><FONT SIZE=3D2>To: powerh-l@lists.swau.edu</FONT>
<BR><FONT SIZE=3D2>Subject: Powerhouse 4GL RDBMS Question - =
Subitems</FONT>
</P>
<BR>
<P><FONT SIZE=3D2>With IMAGE DB you can define Subitems in Powerhouse =
which is nothing else as</FONT>
<BR><FONT SIZE=3D2>using one single field out of the database and =
defining a data structure</FONT>
<BR><FONT SIZE=3D2>within Powerhouse for this single DB field using the =
PHD (Powerhouse</FONT>
<BR><FONT SIZE=3D2>Dictonary).</FONT>
</P>
<P><FONT SIZE=3D2>Example:</FONT>
<BR><FONT SIZE=3D2> Field in IMAGE =
DB: X CHAR(10)</FONT>
<BR><FONT SIZE=3D2> Subitems in Powerhouse =
using field X of IMAGE DB:</FONT>
<BR><FONT =
SIZE=3D2> &nb=
sp; =
subitem1 CHAR(3)</FONT>
<BR><FONT =
SIZE=3D2> &nb=
sp; =
subitem2 CHAR(3)</FONT>
<BR><FONT =
SIZE=3D2> &nb=
sp; =
subitem3 CHAR(4)</FONT>
</P>
<P><FONT SIZE=3D2>We are speaking with someone who has told us =
that they have tried to do</FONT>
<BR><FONT SIZE=3D2>this with a relational DB and learned that is under =
the impression that</FONT>
<BR><FONT SIZE=3D2>Powerhouse does not support this ability to overlay =
fields for a</FONT>
<BR><FONT SIZE=3D2>relational DB, only for IMAGE DB. The client went on =
to say that you cannot</FONT>
<BR><FONT SIZE=3D2>define Subitems in the Powerhouse Dictonary for a =
relational DB.</FONT>
</P>
<P><FONT SIZE=3D2>Can someone confirm this?</FONT>
</P>
<P><FONT SIZE=3D2>Charles Finley</FONT>
<BR><FONT SIZE=3D2>Transformix Computer Corporation</FONT>
<BR><FONT SIZE=3D2>(760)-439-3146 </FONT>
<BR><FONT SIZE=3D2>=3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =
=3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D</FONT>
<BR><FONT SIZE=3D2>Mailing list: powerh-l@lists.swau.edu</FONT>
<BR><FONT SIZE=3D2>Subscribe: "subscribe" in message body to =
powerh-l-request@lists.swau.edu</FONT>
<BR><FONT SIZE=3D2>Unsubscribe: "unsubscribe =
<password>" in message body to =
powerh-l-request@lists.swau.edu</FONT>
<BR><FONT SIZE=3D2><A =
HREF=3D"http://lists.swau.edu/mailman/listinfo/powerh-l" =
TARGET=3D"_blank">http://lists.swau.edu/mailman/listinfo/powerh-l</A></F=
ONT>
<BR><FONT SIZE=3D2>This list is closed, thus to post to the list you =
must be a subscriber.</FONT>
</P>
<P><FONT SIZE=3D2>Join us at Cognos' biggest event of the year<I> =
Enterprise 2003, The Cognos Business Forum</I>. Taking place in =
over 25 cities around the world, it's an opportunity for Business and =
IT leaders to learn about strategies for driving performance. Visit<U> =
<A HREF=3D"http://www.cognos.com/enterprise03" =
TARGET=3D"_blank">http://www.cognos.com/enterprise03</A></U> for more =
details. </FONT></P>
<P><FONT SIZE=3D2>This message may contain privileged and/or =
confidential information. If you have received this e-mail in =
error or are not the intended recipient, you may not use, copy, =
disseminate or distribute it; do not open any attachments, delete it =
immediately from your system and notify the sender promptly by e-mail =
that you have done so. Thank you.</FONT></P>
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