Search results
Results from the Health.Zone Content Network
Microsoft Access is a relational database program from Microsoft that combines a graphical user interface and software-development tools. It can store data in its own format or import or link to other databases, and supports Visual Basic for Applications programming language.
Learn how cardinality refers to the uniqueness of data values in a database column and how it affects query optimization. See examples of high-, normal-, and low-cardinality columns and their types.
In relational databases a virtual column is a table column whose value(s) is automatically computed using other columns values, or another deterministic expression. Virtual columns are defined of SQL:2003 as Generated Column, [1] and are only implemented by some DBMSs, like MariaDB, SQL Server, Oracle, PostgreSQL, SQLite and Firebird (database server) (COMPUTED BY syntax).
A star schema is a data model for data warehouses and dimensional data marts that consists of one or more fact tables and dimension tables. Learn about the benefits, types, and examples of star schemas, and how they differ from snowflake schemas.
The MultiDimensional eXpressions (MDX) language provides a specialized syntax for querying and manipulating the multidimensional data stored in OLAP cubes. [1] While it is possible to translate some of these into traditional SQL, it would frequently require the synthesis of clumsy SQL expressions even for very simple MDX expressions.
A view is a result set of a stored query that presents a limited perspective of the database to a user. Learn how views can simplify data, provide security, and support updates, and the difference between read-only and materialized views.
A query plan is a sequence of steps to access data in a SQL database. Learn how to view, understand and improve query plans using graphical, textual or plan table tools.
A surrogate key is a unique identifier for an entity or an object in a database, not derived from application data. Learn about the different definitions, characteristics, advantages and approaches of surrogate keys in current and temporal databases.