Virtual Table
Another term for a view; a table whose data is not physically stored but is generated dynamically from existing tables when queried.
What does Virtual Table mean?
A virtual table is a logical or temporary table that is built dynamically using a query or function rather than physically storing data in a database or GIS systems. When queried, it functions similarly to a standard table, but it retrieves or computes its data dynamically from pre-existing tables or datasets.
Virtual tables are frequently used in GIS contexts to:
Temporarily join the attribute and geographic data.
Make unique views for analysis that avoid data duplication.
When spatial joins or filters are required, run spatial SQL queries (for example, in programs like SpatiaLite or PostGIS).
Large datasets can be handled well with virtual tables, allowing for extensive analysis while enhancing performance and preserving storage.
Related Keywords
In SQL, a virtual table, often called a view, is a structure that resembles a table but does not actually hold data. Rather, it uses a SQL query from one or more underlying tables to dynamically display data. Views make complicated queries easier to understand, improve security by limiting access to particular rows or columns, and offer a means of presenting data in a personalized way without repeating it.
A database A virtual table is a database structure that resembles a table but dynamically displays data in response to queries or other sources rather than physically storing it. Often referred to as a view, it gives users the flexibility and ease of managing data while preserving current information by enabling them to retrieve, filter, or connect data from one or more actual tables without duplicating it.
A view in SQL is a query-created virtual table that displays data from one or more tables without actually storing it. Although it doesn't actually store data, it functions similarly to a table in queries. Any dynamically produced table-like structure, such as views or query results, that is used momentarily during execution is referred to as a virtual table. In essence, not all virtual tables are views, but all views are virtual tables.
In a database management system (DBMS), a virtual table is a table-like object that displays data from one or more real tables without actually keeping it. Typically implemented as a view, it offers a straightforward method of information analysis, limits direct access to sensitive data, and streamlines queries.