Showing papers on "Graph database published in 1970"

On the exchange of information

Abstract: There is widespread and increasing interest in moving information between computer installations which may differ in their hardware, software , or their program libraries and data files [1,2,3]. There is general agreement that the task of making a major program written at one installation available for use at another installation is difficult, and is not seriously undertaken without thorough analysis. Yet there seems to be considerable optimism that the problem of accessing a data base at a foreign installation can be solved through development of a "data description language" that would serve to characterize any class of data objects that might be communicated among computer installations [4]. The purpose of this paper is to argue that the general problem of data exchange is no less difficult than the problem of program exchange, and that the concept of a "data description language" is not a solution to the problem. The Problem To express the general problem of data base transfer, consider two contexts within which procedures may be executed so as to accomp]ish computations on behalf of users. Let these be known as context A and 41 context B. By the term "context" we mean the collection of all those factors that determine the detailled course of execution of computations performed by a computer installation. The factors defining a context for execution of a procedure P are normally these: I. The programming language in which P is expressed for presentation to the computer installation. 2. The compiler for the programming language in which P is expressed. 3. The computer hardware in which the compiled form of P is run. 4. The file manipulation and con~nunications services provided by the operating system of the installation. 5. The set of rules used by the installation for binding external references contained in P. 6. The status of catalogs or directories of data and procedures; the files themselves; the user account under which P is executed. A difference in any of these factors may cause the procedure P to have different effect when performed at two installations. Now let us formulate the problem. A data base D has been created by procedures operating in context A. As shown in Figure la, let Q be representative of these procedures. It is desired to make use of D in a distinct context B. We assume that 'Rake use of D"means that a user wishes to carry out …