A database is collection of data, which contains information about one particular enterprise. The database is used to store information useful to an organization. To repr
Super Key: set of one or more attributes, when taken collectively, can identify uniquely an entity in the entity set. There can be more than one super key of an Entity set.
Candidate Key: The minimal
The query processor is used to interpret the online user’s query and convert it into an efficient series of operations in a form capable of being sent to the storage manager for execution.
A (usually named) set/universe of atomic values, where by "atomic" we mean simply that, from the point of view of the database, each value in the domain is indivisible (i.e., cannot be broken down int
Constraints on databases can be categorized as follows:
·inherent model-based: Example: no two tuples in a relation can be duplicates (because a relation is a set of tuples)
·schema-based: can be e
Storage manager is a program module that provides the interface between the low-level data stored in the database and the application programs and queries submitted to the system.
The storage manager
A transaction is a sequence of one or more SQL statements that together forms a logical unit of work. Each statement in the transaction performs a part of the task, but all of them are required to com
