Lucene99SegmentInfoFormat

Lucene 9.9 Segment info format.

Files:

• .si: Header, SegVersion, SegSize, IsCompoundFile, Diagnostics, Files, Attributes, IndexSort, Footer

Data types:

• Header -->IndexHeader

• SegSize -->Int32

• SegVersion -->String

• SegMinVersion -->String

• Files -->Set<String>

• Diagnostics,Attributes -->Map<String,String>

• IsCompoundFile -->Int8

• HasBlocks -->Int8

• IndexSort -->Int32 count, followed by count SortField

• SortField -->String sort class, followed by a per-sort bytestream (see SortFieldProvider.readSortField)

• Footer -->CodecFooter

Field Descriptions:

• SegVersion is the code version that created the segment.

• SegMinVersion is the minimum code version that contributed documents to the segment.

• SegSize is the number of documents contained in the segment index.

• IsCompoundFile records whether the segment is written as a compound file or not. If this is -1, the segment is not a compound file. If it is 1, the segment is a compound file.

• HasBlocks records whether the segment contains documents written as a block and guarantees consecutive document ids for all documents in the block

• The Diagnostics Map is privately written by IndexWriter, as a debugging aid, for each segment it creates. It includes metadata like the current Lucene version, OS, Java version, why the segment was created (merge, flush, addIndexes), etc.

• Files is a list of files referred to by this segment.

See also