Before analyzing Lucene's index file structure, you should understand the inverted index concept. An inverted index is an inside-out arrangement of documents in which terms take center stage.

Lucene stores the input data in a data structure called an inverted index, which is stored on the file system or memory as a set of index files.

Based on data-distort method, we propose privacy preserving association rules mining algorithm IFB-PPARM using efficient data structure namely inverted file.