Database systems

The systematic lUPAC nomenclature of compounds tries to characterize compounds by a unique name. The names are quite often not as compact as the trivial names, which are short and simple to memorize. In fact, the lUPAC name can be quite long and cumbersome. This is one reason why trivial names are still heavily used today. The basic aim of the lUPAC nomenclature is to describe particular parts of the structure (fi agments) in a systematic manner, with special expressions from a vocabulary of terms. Therefore, the systematic nomenclature can be, and is, used in database systems such as the Chemical Abstracts Service (see Section 5.4) as index for chemical structures. However, this notation does not directly allow the extraction of additional information about the molecule, such as bond orders or molecular weight. 

The JME can also serve as a query input tool for structure databases by allowing creation of complex substructure queries (Figure 2-130), which are automatically translated into SMARTS [22]. With the help of simple HTML-format elements the creation of 3D structure queries is also possible, as were used in the 3D pharmacophore searches in the NCI database system [129]. Creation of reac-... 

If the database is not integrated in a database system, the database is called a flat-frle. As the name indicates, the data arc stored in a file that can be used directly by the user. 

Most database users do not know how the data are organized in a database system (DBS) they depend solely on the application programs. This is sufficient for most database searches where users can receive large amounts of results quickly and easily, e.g., on literature or other information. Nevertheless, a basic knowledge on where and how to find deeper or more detailed information is quite useful. Due to their complex nature, comprehensive searches (e.g., for processes or patents) are not recommended for beginners. However, most local (in-house), online, and CD-ROM databases provide extensive tutorials and help functions that are specific to the database, and that give a substantial introduction into database searching. 

A hierarchical system is the simplest type ofdatabase system. In this form, the var-iou.s data typc.s also called entities (sec figure 5-,3) arc as.signcd. systematically to various levels (Figure 5-5). The hierarchical system is represented as an upside-down tree with one root segment and ordered nodes. Each parent object can have one or more children (objects) but each child has only one parent. If an object should have more than one parent, this entity has to be placed a second time at another place in the database system. 

Typical examples of hierarchical database systems arc the file system of personal computers or the organization of parts (e.g., a construction plan). In the case of car parts, the objects (e.g. B = rear suspension, E = right wheel, J = rim, K = screw) are... 

The network model of a database system is an improvement over the hierarchical model. This model was developed in 1969 by the Data Base Task Group (DBTG) of CODASYL (Conference on Data System Languages) [8, because sometimes the re-... 

This database system is implemented in only a few instances becatisc of its complexity and its liability to errors, although it is a model for the World Wide Web,... 

J.D. Ulmann, J. Widom, A First Course in Database Systems, Upper Saddle River, NJ, Academic Press, 1997. 

T.M. CormoUy, Database Systems A Practical Approach to Design, Implementation and Management, Eds. T.M. Connolly C.E. Begg A.D. Strachan, Wokingham, Addison-Wesley, 1996. 

A. Silberschatz, H. F. Korth, S. Sudar-shan, Database Systems Concepts, 3rd edition, New York, McGraw-Hill, 1997. 

C.J. Date, An Introduction to Database Systems, 6th edition, Addison-Wssley, New York, 1995. 

A PC-based H-nmr database, which includes fiiU spectmm search capabiHty, is being constmcted by the Toyohashi University of Technology (67). Speclnfo, owned by Chemical Concepts, offers a 150,000 spectra Hbrary and database system for mainframe computers, which includes H, F, "O,... 

The National Chemical Laboratory for Industry (NCLl), Japan, has developed an integrated Spectral Database System (SDBS) which is available to users in Japan. AU spectra were deterrnined at NCLl under controUed conditions and are available on a PC/CD-ROM or magnetic tape. The system has both H-nmr (6000 compounds) and C-nmr spectra (5700 compounds), along with searching software. NCLl has also developed an integrated C— H-nmr system that can be used for two-dimensional data elucidation (70,71). 

JICST/JOIS. The Japan Information Center for Science and Technology (fICST) Mass Spectral Database is accessible to users in Japan through the JICST Eactual Database System (fOlS-E). The database uses the NIST/EPA/ MSCD data collection supplemented by spectra from the Mass Spectrometry Society of Japan (84). 

Computer Automated Laboratory System/ Environmental Waste Database System... 

Database system that is designed lo aid in producing both the EPA Manifest and Drum Labels. Includes DOT information for verification. 

FEMA s database system for emergency response information for governments. For use in planning, training, and eventually real-time operational decision-making for all types of emergencies. 

Eastman Chemical Co., 227 Eastman Kodak Company, 227 ECHO , chlorothalonil, 60 ECOTOX Database System, 305 ECOTRIN , asphm, 60... 

Cambridge Structural Database System (2000), v5.21. Cambridge Crystallographic Data Centre, Cambridge... 

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