PLANNING OF THE DATABASE FOR THE VIRTUAL WAREHOUSE
A PROBLEM TO RESOLVE
An important problem to the realization of the database of the Virtual Warehouse regards the
identification of the products that the customer tries. LOGICAL PLANNING The objective of the logical planning is that one to construct a logical outline that can describe,
in correct and efficient way, all the contained information in the outline Is, produced in the phase of conceptual planning.
In the ER one has represented the good demanded with a code and
one description; in truth bottom issue exists one.
Every product has a its identification, a code that, in theory,
would have to allow to identify the good univocamente. Therefore it happens in fact to the source, that is when the good
comes completed comes assigned a code to it trades them univoco for the company manufacturer, and that one would have to be
maintained from the companies that they acquire that good, in such way to allow to easy demand attendance and members of
reciprocation.
Unfortunately, the intermediaries between producer and final customer exist.
The intermediary, that he can as an example be the installations, adds a its personalized code that he overlaps and he
eliminates that one of the producer, rendering the system, the machinery or the irrintracciabile piece for the customer,
if not through the intermediary.
An intermediary has therefore acquired a position privileged and irrenounceable for
the customer, as well as more fort how much the more that good is particular.
This allows it to swell prices and
maintenance of which, in practical, it stops a real monopoly.
An advantage deriving from the adhesion to the
plan of Virtual Warehouse is that one of having the pulizia of these keys of produced identificativo and obtaining one at
least identification univoca to district level. The saving on the purchase, that it would be possible to carry out directly
from the constructor and to a sure inferior price, is inequivocabile.
Simple translation is not one, in how much draft to satisfy two requirements:
The first phase is therefore that one of the restructure of
the outline Entity Relations, and is an independent model from the chosen logical model and it is based on the criteria of
optimization of the outline and simplification of the next phase.
The analysis of the redundancies is the first step,
that is they can be eliminated give to you that they can be derives to you.
This phase already has been held in consideration
during the ER, like also the elimination of external identificatori already has been taken in consideration during the ER,
by means of the inclusion of identificatori of the entities been involved in the external identification.
As an example,
in the entity "warehouse lying", the only attribute would have had to be "value of the lying", while "Identification Warehouse",
"Produced Identification", "Produced Description" is already present between the attributes of "the Demanded" Entity, and
therefore is identification exteriors.
After several passages, which the elimination of the hierarchy,
the join and the separation of the entities, passages that are not present here because ve of it is not need, can
be passed to the translation towards the relational model.
Therefore we will have:
WAREHOUSE (ID_Magazzino, Center, Position GPS, Owner)
The same relation will come then used in order to characterize the yielding warehouse.
Then it is passed to
the emission of the demand for supply:
RICHIESTA_MAG_RICH(ID_Rich_a_MV, ID_Mag_Rich, Quant_Rich, ID_Prod_Rich, "Des_Prod").
The Virtual Warehouse is only and therefore it does not have need of identification of relation.
Through the
demand it is possible to verify the lying near the district warehouses and the other conveyors:
GIACENZA_TRASP
(ID_Trasportatore, ID_Prodotto, Des_Prod, quantitative)
GIACENZA_MAGAZZINO (ID_Magazzino, ID_Prodotto, quantitative Des_Prod)
The Virtual Warehouse emits the bubble then:
BUBBLE (ID_Bolla, ID_Magazzino_Cedente, ID_Prodotto, Des_Prod,
Quantitative, ID_Trasp, Data_Richiesta, Data_Consegna).
In this first phase, but some fields still are settings on
the NULL, because we know only the identificativo of the bubble, of the product, its description and the date of the demand.
All the rest will come compiled with the following operations.
The Virtual Warehouse could choose the distances for several
the conveyors:
DISTANCE (ID_Percorso, ID_Bolla)
after to have some analyzed the cover:
COVER (ID_Percorso, Length, Riforn_Benz, Velocità_Max)
and obviously after to have chosen the conveyors based
on their characteristics:
CARATTERISTICHE_TRASP (ID_Trasp, Coordinate_GPS, Modo_Trasp, Capacità_Max, Trasp Type)
Obviously if the conveyor already has on means the goods, this last passage comes jumped.
With this phase all the
entities and the relations have been transformed in relations of the relational model.
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