2.5 Index Directory File Format

A file in the index directory file format is always associated with a content index, a basic scope index, or a compound scope index. This format consists of several segments, each of which stores a list of index keys selected from the content index file that it is associated with. These segments represent levels of lookup data structures. Each segment is a sorted list of records. Consecutive records are consolidated into fixed-sized batches called index directory pages.

A lookup into an index directory file produces an index key and a position in the associated index file.