Terrier/IndexStructures
This page describes the structures recorded within a typical Terrier 3.x index.
|
Structure Name |
Type |
Implementation |
Constructor Types |
Constructor Values |
|
Random Access Structures |
||||
|
meta |
MetaIndex |
o.t.s.CompressingMetaIndex |
o.t.s.Index, String |
index, structureName |
|
lexicon |
Lexicon<String> |
o.t.s.FSOMapFileLexicon |
String, o.t.s.Index |
structureName, index |
|
lexicon-keyfactory |
FixedSizeWritableFactory |
o.t.s.serialization.FixedSizeTextFactory |
String |
${max.term.length} |
|
lexicon-valuefactory |
FixedSizeWritableFactory |
o.s.s.BasicLexiconEntry$Factory |
|
|
|
document |
DocumentIndex |
o.t.s.FSADocumentIndex |
o.t.s.Index, String |
index, structureName |
|
document-factory |
FixedSizeWritableFactory |
o.t.s.BasicDocumentIndexEntry$Factory |
|
|
|
inverted |
BitPostingIndex or InvertedIndex |
o.t.s.InvertedIndex |
o.t.s.Index, String, DocumentIndex,Class<? extends IterablePosting> |
index, structureName, document, o.t.s.postings.BasicIterablePosting |
|
direct |
BitPostingIndex or DirectIndex |
o.t.s.DirectIndex |
o.t.s.Index, String |
index, structureName |
|
Stream Structures |
||||
|
meta-inputstream |
Iterator<String[]> |
o.t.s.CompressingMetaIndex$InputStream |
o.t.s.Index, String |
index, structureName |
|
lexicon-inputstream |
Iterator<LexiconEntry> |
o.t.s.FSOMapFileLexicon |
String, o.t.s.Index |
structureName, index |
|
document-inputstream |
Iterator<Writable> |
o.t.s.FSADocumentIndex$FSADocumentIndexIterator |
o.t.s.Index, String |
index, structureName |
|
inverted-inputstream |
BitPostingIndexInputStream |
o.t.s.InvertedIndexInputStream |
o.t.s.Index, String, Iterator<LexiconEntry> |
index, structureName,lexicon-inputstream |
Variations are possible according to configuration during indexing:
DirectIndex -> BlockDirectIndex. However, all functionality is exposed by parent class BitPostingIndex.
InvertedIndex -> BlockInvertedIndex. However, all functionality is exposed by parent class BitPostingIndex.
BasicDocumentIndexEntry$Factory -> FieldDocumentIndexEntry$Factory
FSADocumentIndex -> FSAFieldDocumentIndex NB: This change does not happen automatically, but is necessary for efficient field retrieval.
BasicLexiconEntry$Factory -> FieldLexiconEntry$Factory
BasicIterablePosting -> FieldIterablePosting, BlockIterablePosting, or BlockFieldIterablePosting
In addition to the reflected loading of index structures, the following properties are globally used in an index:
num.Terms
num.Tokens
num.Documents
num.Pointers
max.term.length
Various index structures record their own configuration properties in the index.