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Datawasp is a hierarchical database application from Significant Data Systems.
Its notable features are:-
- Coupling of storage structure and end user interface.
- Hierarchical calculation engine which does the same job as SQL but in a hierarchical context.
- Fractal interface.
The data design and end user interface are tightly coupled so that they are edited as a single system instead of separately as is the case in the majority of database managers. The coupling is so tight that much of the interface and design methodology resembles that of a spreadsheet.
The default end user interface follows the hierarchical metaphor but can be focussed on any node in the tree so that the properties of that node are displayed in large prominent controls and sub nodes (with their properties)are shown in tables and nested sub tables . Focussing on a sub node brings that node's properties to the fore and its sub nodes into tables.
Data Structure and storage Datawasp is implemented as a strongly typed Hierarchical database manager. Strongly typed because each node has an explicit user generated type. The types are created with each table and sub table but can be shared between tables. The type definition is effectively that of the table(s) which store objects(rows) of that type. The documentation uses the nomenclature of tables and rows but clearly is designed along object oriented lines - especially when it comes to calculations.
Data is stored in random access files - one for each row 'type' plus one file containing the entire data design. Access to the files by the client can be direct over Windows File Sharing or indirect via a Datawasp server over TCP/IP. Direct file access is trivial to set-up - being the default mode of office networks - but limits performance for some operations over a slow network. Using the server gets over these problems and allows the system to work over the public internet. Direct and indirect access can be used simultaneously on the same database.
Calculations A single expression syntax is used both to access generate calculated values and to generate lists of rows for virtual tables.
Datawasp has its own analogue of SQL to deal with the problems of accessing a hierarchical structure. Expressions use functional notation very similar to that used in a spreadsheet. Expressions can resolve to a single row or to a lists of rows and this mechanism is used to create virtual tables.
All Expressions are resolved in the context of a particular element/row. Whilst rows can be referenced absolutely it is more common for them to be referenced by their position relative to the row for which the element is being resolved. This is proves useful when child rows are being referenced. The functionality of foreign keys is provided by object oriented style references which can be dereferenced in an expression to provide indirection.
Calculation columns - called Derived Values - can be added to tables to effectively provide read only calculated properties.
Although Datawasp is marketed as a Hierarchical database manager it clearly follows some object oriented patterns behind the scenes.
Datawasp's hierarchical structure provides the object oriented concept composition by default. Agrigation is achieved via 'Reference' and 'List of references' data types.
History
Development of DataWasp was started in 2004 and completed in 2008 by Significant Data Systems in the UK. It was released on 22nd of April 2008 and is marketed solely via the trial ware business model.
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