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  2. Trino (SQL query engine) - Wikipedia

    en.wikipedia.org/wiki/Trino_(SQL_query_engine)

    Trino is an open-source distributed SQL query engine designed to query large data sets distributed over one or more heterogeneous data sources. [1] Trino can query data lakes that contain a variety of file formats such as simple row-oriented CSV and JSON data files to more performant open column-oriented data file formats like ORC or Parquet [2] [3] residing on different storage systems like ...

  3. Tuple relational calculus - Wikipedia

    en.wikipedia.org/wiki/Tuple_relational_calculus

    It formed the inspiration for the database-query languages QUEL and SQL, of which the latter, although far less faithful to the original relational model and calculus, is now the de facto standard database-query language; a dialect of SQL is used by nearly every relational-database-management system.

  4. Comparison of data modeling tools - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_data...

    Tool Supported data models (conceptual, logical, physical) Supported notations Forward engineering Reverse engineering Model/database comparison and synchronization

  5. Day count convention - Wikipedia

    en.wikipedia.org/wiki/Day_count_convention

    The day count is also used to quantify periods of time when discounting a cash-flow to its present value. When a security such as a bond is sold between interest payment dates, the seller is eligible to some fraction of the coupon amount. The day count convention is used in many other formulas in financial mathematics as well.

  6. ISO 8601 - Wikipedia

    en.wikipedia.org/wiki/ISO_8601

    [17] The separator used between date values (year, month, week, and day) is the hyphen, while the colon is used as the separator between time values (hours, minutes, and seconds). For example, the 6th day of the 1st month of the year 2009 may be written as "2009-01-06" in the extended format or as "20090106" in the basic format without ambiguity.

  7. Query language - Wikipedia

    en.wikipedia.org/wiki/Query_language

    Cypher is a query language for the Neo4j graph database; DMX is a query language for data mining models; Datalog is a query language for deductive databases; F-logic is a declarative object-oriented language for deductive databases and knowledge representation. FQL enables you to use a SQL-style interface to query the data exposed by the Graph API.

  8. Relational algebra - Wikipedia

    en.wikipedia.org/wiki/Relational_algebra

    Even the query language of SQL is loosely based on a relational algebra, though the operands in SQL are not exactly relations and several useful theorems about the relational algebra do not hold in the SQL counterpart (arguably to the detriment of optimisers and/or users). The SQL table model is a bag , rather than

  9. Comparison of relational database management systems - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_relational...

    An SQL schema is simply a namespace within a database; things within this namespace are addressed using the member operator dot ".". This seems to be a universal among all of the implementations. A true fully (database, schema, and table) qualified query is exemplified as such: SELECT * FROM database. schema. table