The discriminant tells us there are two roots when positive, one root when zero, and no roots when negative. b^2-4ac = (-8)^2-4*3*1 = 52 is positive, so there are two roots. The discriminant is just part of the quadratic equation. The quadratic equation gives us the exact real number roots of any equation in the form ax^2+bx+c=0. The quadratic equation is x = (-b \pm sqrt(b^2-4ac))/(2a), where \pm means that we have two values, one using + (addition) and one using - (subtraction). Let D = b^2-4ac.
A data warehouse is a special type of database used for analysis of data. A general database is usually used for transaction processing, and hence, it is not optimized for analysis and reporting. But a data warehouse is specially designed and optimized for analysis tasks.
Relational databases use tables to store information. The standard fields and records are represented as columns (fields) and rows (records) in a table. With a relational database, you can quickly compare information because of the arrangement of data in columns.