Data description languages

CODASYL Data Description Language Committee, in miation Systems 1987, 3(4), 247-320. 

What features of a data description language will enable a DBMS designer to control independently both the logical and physical properties of data ... 

What features need to be incorporated into a data description language in order to enable errors to be detected at the earliest possible time such that users will not be affected by errors that occur at a time prior to their personal use of the DBMS ... 

The bottom line question that summarizes aU of these is, How does one design a data model and data description language to enable efficient and effective data acquisition, storage, and use There are many related questions one concerns the design of what are called standard query languages (SQLs) such that it is possible to design a specific DBMS for a given application. 

Molecular databases and the associated data banks require the development of a conceptual structure for the information stored about the molecules, descriptive language representing the data, and methods for analysis enabling molecular modeling, similarity searches, classification, visualization, or other uses of the database.320 Currendy, the Protein Data Bank (PDB http 7www.rcsb.org/pdb/) is one of the best known examples of a molecular database. The PDB is a worldwide archive of three-dimensional structural data of biological macromolecules.321 The PDB is a common accentor to many structural databases.322 The success of... 

Each SOAP Web service is described in terms of Web Service Description Language (Booth and Liu 2007), which is a specification in XML. This enables data passed over the Web, say a sequence of characters such as CMRSGGCTRRYAC, to have its type specified according to an ontology, thus telling the code that that sequence of characters is a consensus DNA sequence rather than an author name or a geographical location. A RESTful Web service works in terms of HTTP requests and thus has potentially a less constrained syntax. 

I n this chapter, we discussed how the different types of printers work as well as the most common methods of connecting them to computers. You learned how computers use page description languages to format data before they send it to printers. You also learned about the various types of consumable supplies and how they relate to each type of printer. 

The PHRAN-SPAN natural language interface for system-level specifications, the AGIS graphics interface for directly manipulating the Design Data Structure, the 3DIS data base interface, and the SLIDE hardware description language. 

The CTF description language appears to be flexible enough to describe the vast majority of connection table formats in use today, and extensible enough to be adapted to those likely to arise in the future. A practical limitation of the language as described here is the inability to handle binary data conveniently. If interpretation of binary connection table formats becomes important, binary-oriented translation operators could be added to the language. 

In appendix, a formal description of the model can be found, using the Express language, based on the STEP (STandard for the Exchange of Product model data) standardized approach (ISO 10303). 

With its flexible and logical search language, REACCS can retrieve molecular stmctures, the atoms and bonds that are transformed ia a reaction, relative and absolute stereochemistry, the role (reactant, product, solvent, or catalyst) of a molecule ia a reaction, reaction data (eg, temperature and yield), hterature references, and keyword descriptions of reaction types. 

Objective Evaluation of Color. In recent years a method has been devised and internationally adopted (International Commission on Illumination, I.C.I.) that makes possible objective specification of color in terms of equivalent stimuli. It provides a common language for description of the color of an object illuminated by a standard illuminant and viewed by a standard observer (H). Reflectance spectro-photometric curves, such as those described above, provide the necessary data. The results are expressed in one of two systems the tristimulus system in which the equivalent stimulus is a mixture of three standard primaries, or the heterogeneous-homogeneous system in which the equivalent stimulus is a mixture of light from a standard heterogeneous illuminant and a pure spectrum color (dominant wave-length-purity system). These systems provide a means of expressing the objective time-constant spectrophotometric results in numerical form, more suitable for tabulation and correlation studies. In the application to food work, the necessary experimental data have been obtained with spectrophotometers or certain photoelectric colorimeters. 

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