Procedural language function

The RDBMS is installed and runs on a computer that functions as a database server. Any SQL commands are executed on the server by the RDBMS. Functions written in SQL or in any of the procedural languages mentioned above are also executed by the RDBMS. This has the advantage that the data tables used by these SQL commands or procedural functions are under the control of the server. This is the most efficient way to access the data. The disadvantage is that the server may have many requests to handle from many users. Another way to operate on data tables is indirectly, using a client program typically (although not necessarily) run from another computer. 

There is a smaller set of tools that are typically run on the server. Any SQL commands and any procedural language functions are run on the server. In principle, there is complete flexibility of the server side tools, since in principle any computer program can be written in any computer language. Later chapters of this book show how the RDBMS server itself can be extended using server side programming to handle chemical information. These extensions may directly solve the needs of a particular project, but more importantly they increase the flexibility of the RDBMS to handle chemical information. Client programs can use the results of chemical searches and other computations as well. 

Unlike the procedural languages discussed above, C language functions are compiled separately. The code itself is not included in the SQL create function command. Instead, the create function command refers to a compiled object such as shared object (.so) file located in some directory on the server running the RDBMS. For example, the CHORD oe smiles function is defined as follows. 

This defines the SQL function oe smiles, which is realized by calling the C function oe anysmiles in the shared object file gnova.so. The definition of the input arguments and return values is done in the same way as for a function written in any other procedural language. 

Relational databases are not just for storage and organization of information. While they have always provided useful tools to search data, I now realize how the extensibility of a database increases its usefulness by using various procedural languages operating within the database. I have converted most of my essential tools into database functions. Whenever possible, these tools operate on whole tables rather than processing them using arrays and iterators. It seems now that I am inside the database... 

Local formulas correspond to each type of statement in the VHDL subset. In general, the formalization of a statement consists of two parts flow and function. The flow component captures the program flow implicit in the statement. In traditional procedural languages, flow proceeds from one statement to the next, except for loops and selection statements. In VHDL, the situation is complicated somewhat by the presence of a time dimension for certain statements (e.g. WAIT). The second component of a statement formalization is the functional component, and captures the semantics of the variable values affected by the statement. The functional component is complicated by the presence of statements that affect variable values at a different time (e.g. signal assignment). 

An object-oriented language that is connected to, or derived from, a procedural language base (C-f-1-, though a distinct language, was derived from C CLOS is an extension of Common LISP and incorporates all functions defined in this base language). 

The ASCII input file includes elements of a scripting language. Thus, the input can contain variables, loops, and procedures. This is one of the aspects of the program that makes it possible to do very complex calculations. The documentation describes the input options, but does not discuss when and why they should be used. The user must have a solid understanding of ah initio theory in order to correctly utilize many of the functions in this program. It is very powerful, but not for beginners. 

In standard Pascal, although only in a few implementations of the language, a function or procedure name may also be a parameter to a sub-prograrn. The constants, types, and variables used in a sub-program, as well as those in the main program, must be declared (see following declarations). 

The procedure, which executes verification of remote computer presence in the network. This computer is recognized as computer of potential hacker. This function is executed by the standard instrument of C language namely by using a function connect(). If communication with a remote computer does not exist the procedure must finish its operation ... 

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