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Purpose of the data hierarchy. "Data hierarchy" is a basic concept in data and database theory and helps to show the relationships between smaller and larger components in a database or data file. It is used to give a better sense of understanding about the components of data and how they are related. It is particularly important in databases ...
Database index. A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time said table is accessed.
Overview. Data validation is intended to provide certain well-defined guarantees for fitness and consistency of data in an application or automated system. Data validation rules can be defined and designed using various methodologies, and be deployed in various contexts. [1] Their implementation can use declarative data integrity rules, or ...
Database normalization is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model . Normalization entails organizing the columns ...
In computing, online analytical processing, or OLAP ( / ˈoʊlæp / ), is an approach to quickly answer multi-dimensional analytical (MDA) queries. [1] OLAP is part of the broader category of business intelligence, which also encompasses relational databases, report writing and data mining. [2] Typical applications of OLAP include business ...
A database model is a type of data model that determines the logical structure of a database. It fundamentally determines in which manner data can be stored, organized and manipulated. The most popular example of a database model is the relational model, which uses a table-based format.
In order to retrieve the desired data the user presents a set of criteria by a query. Then the database management system selects the demanded data from the database. The retrieved data may be stored in a file, printed, or viewed on the screen. A query language, like for example Structured Query Language (SQL), is used to prepare the queries.
Lookup table. In computer science, a lookup table ( LUT) is an array that replaces runtime computation with a simpler array indexing operation, in a process termed as direct addressing. The savings in processing time can be significant, because retrieving a value from memory is often faster than carrying out an "expensive" computation or input ...