Hi,

I have index ~31G where
27% of the index size is .fdt files (8.5G)
20% - .fdx files (6.2G)
37% - .frq files (11.6G)
16% - .tim files (5G)

This is the term dictionary for 4.0‘s default codec (currently uses
BlockTree implementation)

.tim is the on-disk portion of the terms (similar in function to .tis
in previous releases)
.tip is the in-memory "terms index" (similar in function to .tii in
previous releases)

见：http://grokbase.com/t/lucene/solr-user/124ha4e1bb/solr-4-0-what-is-stored-in-tim-index-file-format

lucene 索引文件大小分布_tim