Re: RTB Schema

From: Patrick Tingen

Date: 28 Nov 2001

Geoff,

Yep, you are missing something, but some elements of my text got lost during
conversion to a text-based mail so I don't blame you ;-)

What you missed, was the index information on the second scheme, therefore:
a retry.

<courier>
  .--------.        .------------.
  | object | >----- | objecttype |
  .--------.        .------------.
     |
     ^
  .----------------.        .----------.        .--------------.
  | relationmember | >----- | relation | >----- | relationtype |
  .----------------.        .----------.        .--------------.
</courier>

Object:  (iOBJECTNR, cObjectName, cObjectType)
Relation:  (iRELATIONNR, cRelationType)
RelationMember: (iRELATIONNR, iOBJECTNR)
Objecttype:  (cOBJECTTYPE
Relationtype:  (cRELATIONTYPE)

Primary (unique) indexes are in caps.

To make it even more clear, here's what the tables' contents might look
like:

Object:
Nr name          type
1  myprogram.p   procedure
2  myinclude.i   include
3  mytable       file
4  myfield       field

Relation:
Nr type
1  include
2  file-field
3  access

RelationMember
RelNr  ObjNr
  1      1                        represents a relation between myprogram.p
and myinclude.i
  1      2
  2      3                        represents a relation between mytable and
myfield
  2      4
  3      1                        represents a relation between myprogram.p
and myfield
  3      4

As you can see, the relation-table is no more than a 'holder' for the
relations. The actual relations are stored in relationmember. Strictly
spoken, the table relation is redundant : its contents can be derived from
relationmember.

gr

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
P a t r i c k   T i n g e n

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----- Original Message -----
From: "Geoff Crawford" <b21b0721-86d0-328b-de11-69013e0103b7>
To: <>
Sent: Tuesday, November 27, 2001 8:23 AM
Subject: Re: RTB Schema

. snip ...

>
> I must be missing something here.  The first scheme
> related two different objects, the parent and the
> child.  This seems to only ever refer to one
> object via the RelationMember.
>
> ===================================================================
> Geoff Crawford                         Phone:      (973) 361 - 4224
> Innovative Client Servers              FAX:        (973) 537 - 6946
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>