In this particular learning path, we will look at principles and methods of data retrieval. So we will try to understand certain principles of data extraction such as Tuple selection, Attribute projection as well as methods of data querying. Thus we will also look at the elementary query operators.
First and foremost, we let us reflect on Database as a concept in this learning path as already being taught under Data Management I.
Besides reflecting on Database as a concept, it is equally we do so for Relational Database, which is our next element in this path.
This then takes us to the concept of Relation as already being treated earlier under Data Management I.
As part of our whipping up our understanding on ways to use query operators for data retrieval we once again look at Attribute (sames as Data Attribute) and Tuple as properties of Relation. First of all, we look at the term Attribute.
The next term for our consumption subsequent to our attempt to start data querying is Tuple.
It is equally important we remember what Domain means.
This takes us to the language of querying spatial data with Structured Query Language (SQL).
Now in this learning path, we will give emphasis to what "Tuple selection" is, which works like a filter.
The next terminology worth of our understanding in this path is "Attribute Projection", which is works like a :"tuple formatter".
We now look at query as an item to know the steps involve in data querying.
Selection condition is the next thing we will considered in this learning path so as to know the truth statement about Tuple's Attribute values.
Last but not least concept for our consumption in this learning path is the term "Join", which allows the opportunity to take input relations and produce one output relation. Join is form of "gluing"one relation with another to create a new relation/table.