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To create a treemap, one must define a tiling algorithm, that is, a way to divide a region into sub-regions of specified areas.Ideally, a treemap algorithm would create regions that satisfy the following criteria:
Treemap: Treemap: size; color; Is a method for displaying hierarchical data using nested figures, usually rectangles. For example, disk space by location / file type; Gantt chart: Gantt chart: color; time (flow) Type of bar chart that illustrates a project schedule; Modern Gantt charts also show the dependency relationships between activities ...
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 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. Many graphical front-ends for databases use the ideas from QBE today.
The formal definition of a database schema is a set of formulas (sentences) called integrity constraints imposed on a database. [citation needed] These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible in the same language.
The Oxford English Dictionary records use of both the terms "tree structure" and "tree-diagram" from 1965 in Noam Chomsky's Aspects of the Theory of Syntax. [2] In a tree structure there is one and only one path from any point to any other point. Computer science uses tree structures extensively (see Tree (data structure) and telecommunications.)
Report Definition Language (RDL) is a standard proposed by Microsoft for defining reports. [1] RDL is an XML application primarily used with Microsoft SQL Server Reporting Services. It is usually written using Visual Studio, although there are also third-party tools; it may also be created or edited by hand in a text editor.
Prior work by WG3 and SC32 mirror bodies, particularly in INCITS Data Management (formerly INCITS DM32), has helped to define a new planned Part 16 of the SQL Standard, which allows a read-only graph query to be called inside a SQL SELECT statement, matching a graph pattern using syntax which is very close to Cypher, PGQL and G-CORE, and ...