Query operators

Convenient attributes To simplify all specifications to make algorithmic query operations trivial to make specifications more natural. 

Data storage and querying are the most fundamental requirements of all informatics systems. Thanks to the Oracle Extensibility Framework (a.k.a. Oracle Data Cartridge Technology), chemical structure data can be stored and queried using direct SQL and special query operators, such as substructure search, flexmatch search, similarity search, and formula search. Also, some indexing techniques make these otherwise slow searches fast. Detailed discussions about these databases and cartridges are beyond the scope of this book. Please refer to the vendor s website and product documentation for more information. 

Readers who are familiar with the MDL database should not be surprised to see MDL s structure query operators such as sss, molsim, and flexmatch. The CompoundMapper s StatementSource objects use ChemDBQueryBuilder to append these structure search operators to the structure search SQL statements. Take the substructure search as an example. In CompoundMapper, we have an inner class FindBySubstructure whose getSql() method is as follows ... 

In every step of the query, users can sec examples given by the program, in order to guide them through the literature search. Thus, a novice user can operate this system immediately. 

The trained counterpvopagation network is then able to predict the spectrum for a new structure when operating as a look-up table (see Figure 10.2-9) the encoded query or th.c input structure is input into the trained network and the winning neuron is determined by considering just the upper part of the network. The neuron points to the corresponding neuron in the lower part of the network, which then provides the simulated IR spectrum. 

REACCS is organized iato six operational modes MAIN and BUILD, which are used to draw molecular stmctures, build reactions, and constmct graphic queries and SEARCH, VIEWLIST, PLOT, and EORMS, which are used to create custom forms to display data associated with reactions and molecules. Each of the modes provides a characteristic menu and a set of options, which normally perform tasks that relate to the general function of that mode. 

The RMDB may be queried directly by qualified participants. Data needed urgently may be obtained by an Urgent Data Request (UDR) sent to the GIDEP Operations Center. 

The construction worker who was to cairy out the modification checked the cable with a current detector and found that the wrong one had been disconnected. It was then found that the cable was incorrectly described on the written instmctions given to the operators. The description of the cable was not entirely clear, but instead of querying it, the first operator decided what he thought was the correct cable and asked the electrician to disconnect it. The second operator, or checker, had not been trained to check cables [32]. 

By clicking the appropriate buttons on the form, the user can combine molecular structure queries of sample, CSP and solvent, using operators AND, OR, NOT with data queries in one search. A query for the search of chiral separations of alpha-aromatic acids on any polysaccharide phases coated on silica gel providing an alpha value superior to 1.2 is shown in Eig. 4-4. 

There are documented procedures in operation for ascertaining customer satisfaction and handling queries and complaints and system failures. 

A good operation specification is much like a test specification. With a little infrastructure support—such as query functions to map from concrete data representations to the abstract attributes used in the specifications and some means to capture initial values of attributes—these operation specifications can be mapped to test code that is executable at runtime, at least during testing or debugging. 

The operation specs often map directly to tests. Thus, the spec for squareRoot easily translates into test code so does schedule course, after we write query functions to determine attributes related to instructor qualification and availability in terms of the concrete implementation. Some specifications may need to be refactored a bit to be tested effectively. A literal usage of takeShortestPath as a test specification would require generating all possible paths to show that the computed path is the shortest, but that s not a very practical test strategy.10... 

A parameterized attribute, such as alternateSessions(dates), is an abstraction of state. When it is implemented, there will be a way to determine the value of that attribute for each applicable value of the parameter in its range. In this sense, it can be easily confused with a read-only operation a query that can be invoked as a service returns a value and has no side effect. We choose to distinguish clearly between state abstractions (attributes) and invocable operations. 

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