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  2. Aggregate (data warehouse) - Wikipedia

    en.wikipedia.org/wiki/Aggregate_(data_warehouse)

    The aggregate navigation essentially examines the query to see if it can be answered using a smaller, aggregate table. [5] Implementations of aggregate navigators can be found in a range of technologies: OLAP engines; Materialized views; Relational OLAP services; BI application servers or query tools

  3. Query by Example - Wikipedia

    en.wikipedia.org/wiki/Query_by_Example

    Query by Example (QBE) is a database query language for relational databases. It was devised by Moshé M. Zloof at IBM Research during the mid-1970s, in parallel to the development of SQL . [ 1 ] It is the first graphical query language, using visual tables where the user would enter commands, example elements and conditions.

  4. QUEL query languages - Wikipedia

    en.wikipedia.org/wiki/QUEL_query_languages

    QUEL is a relational database query language, based on tuple relational calculus, with some similarities to SQL.It was created as a part of the Ingres DBMS effort at University of California, Berkeley, based on Codd's earlier suggested but not implemented Data Sub-Language ALPHA.

  5. Aggregate function - Wikipedia

    en.wikipedia.org/wiki/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; Minimum; Mode ...

  6. pandas (software) - Wikipedia

    en.wikipedia.org/wiki/Pandas_(software)

    Pandas is built around data structures called Series and DataFrames. Data for these collections can be imported from various file formats such as comma-separated values, JSON, Parquet, SQL database tables or queries, and Microsoft Excel. [8] A Series is a 1-dimensional data structure built on top of NumPy's array.

  7. Data query language - Wikipedia

    en.wikipedia.org/wiki/Data_query_language

    The purpose of DQL commands is to get the schema relation based on the query passed to it. Although often considered part of DML, the SQL SELECT statement is strictly speaking an example of DQL. When adding FROM or WHERE data manipulators to the SELECT statement the statement is then considered part of the DML.

  8. Query language - Wikipedia

    en.wikipedia.org/wiki/Query_language

    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).

  9. Select (SQL) - Wikipedia

    en.wikipedia.org/wiki/Select_(SQL)

    The SQL SELECT statement returns a result set of rows, from one or more tables. [1] [2] A SELECT statement retrieves zero or more rows from one or more database tables or database views. In most applications, SELECT is the most commonly used data manipulation language (DML) command. As SQL is a declarative programming language, SELECT queries ...