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4.1.- Concepts

Preliminary Concepts:

Data Server:
For all us, a Data Server is a machine that has inside its file system one or more (it depends of database engine) files that contains tables, views or relations (with or without other database objects); all related between themselves, so it is a single unit of data. The Personal Edition can manage more than one data servers but not more than one at the same time.
Data Environment:
This concept is specific to Store/Enterprise Edition. The complete network of an enterprise is the top-level data environment. This environment is compounded by one or more dataservers (running the jLaBase Application Server) which store data related between them. In this network can exist other sub-environments relative to the main data environment of the enterprise, so each data environment defines a naming context. The initial context of the network is the Top-Level Data Environment.
Dataset:
Amount of data retrieved from the data server or a XML file. This is because we wanna be able to do exports on lite files and share them. In this context we will work with "real" datasets that extract data from database and XML datasets that do the same but using a XML file as source. Each dataset has a qualified name binded to the dataset object, by this way we can reference datasets using URL's jLaBase
Detail Field:
Entity's field that represents a many-to-one relation with a detail value set.

Entities & Relations:

Entity/Corporative Entity:
We will call "corporative entity" (or simply "entity") to every database object (table or view) that browses data (as a traditional database entity). One of the features of Oracle is that it treats database view objects as real database tables so we can do updates in that entities, the Oracle transactional system is the responsible of direct each data value to the corresponding database table. When working with other data engines (Personal Edition), we must implement the way the field values should be directed to each dataset when this dataset is a database view object.
Optional Entity:
It is an entity as defined above that is not necessary for the minimal function of the data server. If it exists it gives more complexity to the data environment and allows the enterprise data to be more organized.
Corporative Relation:
This is a special kind of relation. A relation of this kind is one that joins two (or more) datasets stored in different servers than the one that holds the relation. A relation that joins datasets stored in the same server that holds the relation will be treated as a loopback relation.
Loopback Relation (only Store/Enterprise Edition):
This relation exists for simplify the application server implementation. In Store/Enterprise Edition all of the realations will be corporative relations, but we will found relations that join datasets in the same server that holds the relation, in this case, the URL's server will be "localhost:port".
Optional Relation:
It can be a corporative relation or a loopback relation. This specific kind of relation joins two or more entities that one or all of them are optional entities.
Note: Personal Edition treats all relations like traditional database relations because we only are connected to one server at the same time.

Environment Users

jLaBase Administrator (lbadmin):
The superuser of the jLaBase Environment, there can be more than one with different level of permissions. In some cases the lbadmin should know something about database relations to build the corporative structure; in other cases the lbadmin can be a simple home user.
jLaBase Seller (lbseller):
The user who has permissions to store new Sales/Borrow, Supply relations. He can also store new entities of Articles, Services, Customers and Manufactor's but not in the Detail entities, he can't also delete records in none of the entities, it is resposability of the lbadmin. Updates in the entity's detail field values are permitted.
jLaBase Customer (lbcustomer):
A user registered in the server who can do searchs, query sales/borrows and do reserves of articles. This permissions should be restricted by the lbadmin.
jLaBase Visitor (lbvisitor):
A user not registered in the server, he can do searchs and queries, but he can not buy or rent any article or receive any service.

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