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Microsoft Access. Microsoft Access is a database management system (DBMS) from Microsoft that combines the relational Access Database Engine (ACE) with a graphical user interface and software-development tools. It is a member of the Microsoft 365 suite of applications, included in the Professional and higher editions or sold separately.
The star schema is an important special case of the snowflake schema, and is more effective for handling simpler queries. The star schema gets its name from the physical model's resemblance to a star shape with a fact table at its center and the dimension tables surrounding it representing the star's points.
SQL includes operators and functions for calculating values on stored values. SQL allows the use of expressions in the select list to project data, as in the following example, which returns a list of books that cost more than 100.00 with an additional sales_tax column containing a sales tax figure calculated at 6% of the price.
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, and are only implemented by some DBMSs, like MariaDB, SQL Server, Oracle, PostgreSQL, SQLite and Firebird (database server) (COMPUTED BY syntax).
Query plan. A query plan (or query execution plan) is a sequence of steps used to access data in a SQL relational database management system. This is a specific case of the relational model concept of access plans. Since SQL is declarative, there are typically many alternative ways to execute a given query, with widely varying performance.
Online analytical processing. 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]
Microsoft Query is a visual method of creating database queries using examples based on a text string, the name of a document or a list of documents. The QBE system converts the user input into a formal database query using Structured Query Language (SQL) on the backend, allowing the user to perform powerful searches without having to ...
Aggregate function. In database management, an aggregate function or aggregation function is a function where multiple values are processed together to form a single summary statistic . (Figure 1) Entity relationship diagram representation of aggregation. Common aggregate functions include: Average (i.e., arithmetic mean) Count. Maximum. Median.