Search results
Results from the WOW.Com Content Network
It is based on the probabilistic retrieval framework developed in the 1970s and 1980s by Stephen E. Robertson, Karen Spärck Jones, and others. The name of the actual ranking function is BM25 . The fuller name, Okapi BM25 , includes the name of the first system to use it, which was the Okapi information retrieval system, implemented at London ...
Fast aggregations – the simpler queries against a star schema can result in improved performance for aggregation operations. Feeding cubes – star schemas are used by all OLAP systems to build proprietary OLAP cubes efficiently; in fact, most major OLAP systems provide a ROLAP mode of operation which can use a star schema directly as a ...
A result set is the set of results returned by a query, usually in the same format as the database the query is called on. [1] For example, in SQL, which is used in conjunction with relational databases, it is the result of a SELECT query on a table or view and is itself a non-permanent table of rows, and could include metadata about the query such as the column names, and the types and sizes ...
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Edgar F. Codd [12] in the early 1970s. [13] This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasirelational database management system, System R, which a group at IBM San ...
It supports the MDX query language, the XML for Analysis and the olap4j interface specifications. Apache Doris is an open-source real-time analytical database based on MPP architecture. It can support both high-concurrency point query scenarios and high-throughput complex analysis. [31]
The key feature of spreadsheets is the ability for a formula to refer to the contents of other cells, which may, in turn, be the result of a formula. To make such a formula, one replaces a number with a cell reference. For instance, the formula =5*C10 would produce the
A query language, also known as data query language or database query language (DQL), is a computer language used to make queries in databases and information systems. In database systems, query languages rely on strict theory to retrieve information. [1] A well known example is the Structured Query Language (SQL).
Much of the data that makes up the Wikipedia encyclopedia is stored in a SQL database. It can sometimes be useful to run queries against this database to extract information that is otherwise hard to find. For example: Articles with H.M.S. in their title that have not been edited for 12 months.