The basis for the difference between a database and a data warehouse arises from the fact that a data warehouse is a type of database that is used for data analysis. A database is an organized collection of data stored on a computer system. Information about students, teachers, and classes in a school stored in table fashion is an example for a database. As databases support large amount of data, concurrent processing, and efficient operations, they are widely used. But, as database is often subjected to updates, it not possible to have a proper view to do an analysis. Hence, a data warehouse technique must be followed to achieve this. A data warehouse is a special type of database, but which is optimized for querying and analysis. As a data warehouse extracts data from various sources and reports, it does so that decisions can be reached by analysis. Let us look at them and the difference between them in more detail here.
What is a Database?
A database is a collection of related data stored on a computer system. Usually, a database is organized and its data is related. For example, a school database would have several tables as teachers, students, and classes where each table would have records that specify information about each item. Here, we can see the structure is organized based on certain criteria and there are relationships between the tables as they all belong to the same school. A database has numerous uses in the computer world. Therefore, it is so famous that it is found very abundantly in various applications. The basic advantage of a database is that a database can store a huge amount of data in a very less space while providing very fast and easy operations on data.
A database often involves a software system called Database Management System (DBMS), which is responsible for storing and managing the data in the database. MySQL, Oracle, Microsoft SQL Server are some well-known database management systems. When creating a database on the computer, first step is to create a logical structure of how data is stored, organized, and manipulated based on the description we have for the system. This is called as database modeling. There are various modeling techniques such as relational model, network model, object oriented model, and hierarchical model, but the most famous one is the relational model. Even MySQL, which is one of the most used database management systems, uses the relational model to store its databases.
Database Models
A database supports four functions that is given by the acronym CRUD that refers to create, read, update, and delete. In SQL, create lets you insert data to a table. Read lets you query what you want to retrieve and update lets you modify data when it is necessary. Delete lets you delete data when they must be done so.
What is a Data Warehouse?
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. A data warehouse usually fetches data from the history of a transaction processing system while various other sources also can contribute. After extracting data from various sources, they are reported in a generalized view. A transaction processing system involves lots of operations per second and hence data is often updated making it difficult for someone to view it at a certain point and analyze it to reach a decision. A data warehouse exactly enables this by extracting information and reporting it in a neat fashion such that one can analyze it to reach a decision.
What is the difference between Database and Data Warehouse?
A database is an organized collection of data. A data warehouse is a special type of database, which is optimized for querying and reporting rather than transaction processing. So following comparison is done about a general database and a data warehouse.
• A database stores current data while a data warehouse stores historical data.
• A database often changes due to frequent updates done on it, and hence, it cannot be used for analysis or reaching decision. A data warehouse extracts data and reports them to analyze and reach decisions.
• A general database is used for Online Transactional Processing while a data warehouse is used for Online Analytical Processing.
• Tables in a database are normalized to achieve efficient storage while a data warehouse is usually demoralized to achieve faster querying.
• Analytical queries are much faster on a data warehouse than on a database.
• A database contains highly detailed data while a data warehouse contains summarized data.
• A database provides a detailed relational view while a data warehouse provides a summarized multidimensional view.
• A database can do a lot of concurrent transactions while a data warehouse is not designed for such tasks.
Summary:
Data Warehouse vs Database
A database is an organized collection of data stored on a computer system. It stores a large amount of data and they often change due to various updates. Therefore, it cannot be used for an analysis to reach a decision. So a data warehouse is used. A data warehouse extracts data from various sources including general databases and then report them in a convenient fashion to easily do an analysis. An important difference is that a database contains current data while a data warehouse contains historical data. A database is used for transaction processing while a data warehouse is used for analytical processing.
Images Courtesy:
- Collage of five types of database models by Marcel Douwe Dekker (CC BY-SA 3.0)
- Data warehouse via Wikicommons (Public Domain)