Write a program that stores names and telephone numbers in a database. Write another program that stores names and addresses in a database. Modify the programs to use external, conceptual, and internal schemas. What are the advantages and disadvantages of this modification?
What will be an ideal response?
The programs can be written in any suitable language and should be well structured and
appropriately commented. Two distinct files result. The structures can be combined into one
containing name, address, and telNo, which can be the representation of both the internal and
conceptual schemas. The conceptual schema should be created separately with a routine to map
the conceptual to the internal schema. The two external schemas also must be created separately
with routines to map the data between the external and the conceptual schema. The two programs
should then use the appropriate external schema and routines.
You might also like to view...
Consider the algorithm given in Figure 15.17for consensus in a synchronous system, which uses the following integrity definition: if all processes, whether correct or not, proposed the same value, then any correct process in the decided state would chose that value. Now consider an application in which correct processes may propose different results, e.g., by running different algorithms to decide which action to take in a control system’s operation. Suggest an appropriate modification to the integrity definition and thus to the algorithm.
What will be an ideal response?
Which statement does NOT describe fifth-generation languages?
A) The system of facts can be queried. B) They are the most "natural" of languages. C) Problems are presented as a series of facts or constraints rather than as a specific algorithm. D) They use a set of short, English-based commands (such as SUB) that speak directly to the CPU.
Design themes are limited to 11 in the PowerPoint Web App
Indicate whether the statement is true or false
# is the Word operator for multiplication
Indicate whether the statement is true or false