I am going through Relational Database Design by JLM. I have come across words like database, data model, DBMS etc. which I am able to understand. But, I get confused when the author tries to use Database and Database Environment with supposedly different meaning (as per my understanding).
What does Database Environment make up ?
I understand that data model defines relationship of the data whereas DBMS is data model specific and translated data manipulation requests and retrieves data from physical storage device(s). The author defined Database as data and its relationship.
Where does Environment come into picture ?
This is where I got confused :
underlying relationships in a database environment are independent of the data model and therefore also independent of the DBMS you are using
BTW Am I reading the right book to start with, considering am just beginning?
3
According to Oracle
Database environments encapsulate one or more databases
So an example of dealing with more than one database: one database for the Accounting package, one for the HR system, possibly on the same server (depends on your licencing model) and you’re concerned with the interfaces between them that are required to pay your wages…
2
The term “database environment” is not as clearly defined as the other terms you mentioned. So it can have different meanings in different contexts. For example, if refering to Oracle’s documentation, it may have the meaning as in the post of @mcottle. In a more general context, it could mean just “the database infrastructure of a company or organization” – the available databases, the available client/server infrastructure, the available database APIs, and so on.
So to understand the citation, you need to clarify the context of that statement. Maybe the author is talking about “underlying relationships of a companies data, independently from how this data is modeled”?
The key term here is the term “underlying relationships” [1] which in order to refer to something independent of the DBMS and data model must refer to facts about the objects being modeled. And thus it would seem that “database environment” refers to the context motivating design [2] and use of a database irrespective of whatever means are used to implement the database.
Or to use it in a sentence, “Databasers database in a database environment.” The environment extends outside the computer and is the messiness the DBMS and data model are meant to corral.
[1] Note these are relationships not relations.
[2] Note the book is about design.