Trends in Data Organization and Access Methods

There has been a trend in applications programming over the past fifteen years from highly structured programs and loosely structured data toward loosely structured programs and highly structured data. Transaction oriented systems and other data directed programs make greater demands on the memory hierarchy of a computer system and have given rise to the need for storage media which are to some degree structurable under program control. Overhead in operating systems and large on-line application programs is described as a symptom of "static" and "dynamic" mismatch problems in the storage hierarchy. Some new memory organization techniques beginning to appear on computers may allow greater efficiency in data directed systems since they allow the programmer to store the structure and the content of his data separately.