Road test: Four databases tested: Builder AU: Architect: Database: "

What is it?

* Database: A database is a collection of related information stored in a structured format.
* Relational Database: A collection of 'related' databases, for example and travel agent booking system consisting of customer, airline and account details, can be combined and would be referred to as a Relational Database.
* Record: A database comprises of records and each record contains all the information about a single member or item.
* Field: A record comprises of fields where each field is a single piece of information relating to the record for example your Medibank record may contain individual fields for first name, last name, Medibank number, date of birth, etc. All records have the same structure and so contain the same fields but obviously each field has its own unique data.
* DBMS: Database Management System.
* RDMS: Relational Database Management System.
* Constraint: A constraint is a property assigned to a column or the set of columns in a table that prevents inconsistent data values from being placed in the column/s. They are used to enforce data integrity and therefore database reliability. There are several types of data integrity including Entity, Domain, Referential and User-Defined.
* Dirty read: If a database allows a user to read updated data that has not been 'committed' by the user inputting the data then this is called a dirty read. A database should only allow data to be read that has been committed.
* Query optimiser: When you perform a report or query the optimiser is responsible for determining the fastest and most efficient way to perform the operation. Often the query optimiser relies on table and index statistics to determine the best way to optimise the operation.
* Primary key: The Primary key is a field that uniquely identifies each record in t"