What Does Extremely Large Database Mean?
An extremely large database (XLDB) is a database that stores and processes enormous amounts of data and associated records and entries. As the largest database form factor, XLDB is created and managed by very few organizations around the world, typically scientific research institutes that have massive data sets at their disposal.
Techopedia Explains Extremely Large Database
XLDB works like a standard database, but sheer size differentiates it from normal and very large databases (VLDB). XLDB may include hundreds of petabytes (PB) of data stored on a massive pool of storage devices and supporting infrastructure.
XLDB was conceived in 2007 by the Scalable Data Systems Group at SLAC, a Stanford University research department, while designing a database system for an astronomical survey institute.
Since then, a body by the name of XLDB was formed to identify the trends and challenges of building XLDBs, while combining similar interest groups for future development.