An MPP database is a massively parallel processing database (MPP stands for Massively Parallel Processing).
Massively parallel processing refers to the use of a large number of processors (or separate computers) to perform a set of coordinated computations in parallel (simultaneously).
Each of those two models has their strengths and weaknesses. By combining the two models, a DBMS can take advantage of various strengths from each model.
OODBMS stands for Object-Oriented Database Management System.
An object-oriented database management system (also known simply as an object database) is a DBMS where data is represented in the form of objects, as used in object-oriented programming.
In contrast to relational database management systems (RDBMSs), where data is stored in tables with rows and columns, an object-oriented database stores complex data and relationships between data directly, without mapping to relational rows and columns.
A database management system is an application that enables the creation and administration of databases. Database management system is a broad term that includes any system that performs that function.
The most common type of DBMS is an RDBMS (Relational Database Management System). RDBMSs allow you to create relational databases – databases that have multiple tables that contain related data.
Different database management systems define schema in their own way. This can make it difficult for database developers to work out exactly what a schema is – especially when switching between different DBMSs.
This article provides definitions used by the three leading database systems.
In database terms, a schema (pronounced “skee-muh” or “skee-mah”) is the organisation and structure of a database. Both schemas and schemata can be used as plural forms.
A database schema can be represented in a visual diagram, which shows the database objects and their relationship with each other.
A basic schema diagram representing a small three-table database.
Above is a simple example of a schema diagram. It shows three tables, along with their data types, relationships between the tables, as well as their primary keys and foreign keys.
An orphaned record is a record whose foreign key value references a non-existent primary key value.
Orphaned records are a concept within database relationships. If a row in a related table references a non-existent row in the primary table, it is said to be an orphaned row. This is because it has no “parent” with which its data is associated with. The terms orphaned row and orphaned record tend to be used interchangeably, even though there’s a subtle difference between a row and a record.
Referential integrity refers to the accuracy and consistency of data within a relationship.
In relationships, data is linked between two or more tables. This is achieved by having the foreign key (in the associated table) reference a primary key value (in the primary – or parent – table). Because of this, we need to ensure that data on both sides of the relationship remain intact.
So, referential integrity requires that, whenever a foreign key value is used it must reference a valid, existing primary key in the parent table.