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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:
The nested set model is a technique for representing nested set collections (also known as trees or hierarchies) in relational databases.. It is based on Nested Intervals, that "are immune to hierarchy reorganization problem, and allow answering ancestor path hierarchical queries algorithmically — without accessing the stored hierarchy relation".
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 ...
Most database management systems are built around one particular data model, although it is possible for products to offer support for more than one model. Various physical data models can implement any given logical model. Most database software will offer the user some level of control in tuning the physical implementation, since the choices ...
Using links, records link to other records, and to other records, forming a tree. An example is a "customer" record that has links to that customer's "orders", which in turn link to "line_items". The hierarchical database model mandates that each child record has only one parent, whereas each parent record can have zero or more child records.
A database management system (DBMS) is a computer program (or more typically, a suite of them) designed to manage a database, a large set of structured data, and run operations on the data requested by numerous users. Typical examples of DBMS use include accounting, human resources and customer support systems.
A physical data model (or database design) is a representation of a data design as implemented, or intended to be implemented, in a database management system. In the lifecycle of a project it typically derives from a logical data model , though it may be reverse-engineered from a given database implementation.
The database schema is the structure of a database described in a formal language supported typically by a relational database management system (RDBMS). The term " schema " refers to the organization of data as a blueprint of how the database is constructed (divided into database tables in the case of relational databases ).