design and implementation of a real time information storage and retrieval system
Presented here is a paper on the Design and Implementation of a Real Time (On Line) Information Storage and Retrieval System. Guidance is given into the design and testing of a hashing function for a volatile set of alphanumeric keys. The interrelationship between the hashing function and the Information Storage and Retrieval (IS&R) System is examined with respect to design criteria. Finally the design of the IS&R System itself is presented in terms of an attempt to optimize the Input/Output (I/O) time versus disk and memory storage for a volatile set of records. Built into the IS&R System design is the flexibility to optimize the systems performance under both the ideal and worst case hashing function design or performance. Emphasis, in the design, is placed on the I/O time required in updating, or inquiring, the file for a matched record retrieval. The following techniques were combined to form the original IS&R System: data structures, directory (dictionary) concept, bit directories, link listing (chaining), hashing function, and minimization of disk head movement. The theory of the IS&R System is derived in general and is applicable to a variety of applications as long as the application possess the following requirements: a highly volatile set of records, a real time (or on line) retrieval requirement, difficulty in designing (or choosing) a hashing function due to the volatile set of keys, and heavy activity on updating, or inquiring, the file. Detailed algorithms of the system design are presented for this purpose.
hashing function design data structures bit directory link listing indexing file searching data base design garbage collection directory structures hash addressing scatter storage volatile file real time retrieval retrieval system design list compression