> So, can doc values be persisted with order of values, not document id? This > should be fast in sort scenario that the values are pre-ordered instead of > scan/sort at runtime.
No, unfortunately doc values cannot be persisted in order. Lucene stores this values internally as a DocValuesType.SORTED_SET, where the values are being stored using for example Long.compareTo(). If you'd like to retrieve the values in insertion order, use stored instead of doc values instead of. Then you might access the values in order using the LeafReader's document function. However, beware that may induce performance issues because it requires loading the document from disk. If you require to store and retrieve multiple numeric values per document in order, you might consider using PointValues. PointValues are internally indexed with KD-trees. But, beware that PointValues have a limited dimensionality, in terms that you can for example store values in 8 dimensions, each of max 16 bytes. > On 5 Mar 2018, at 15:33, Tony Ma <t...@opentext.com> wrote: > > Per my understanding, doc values (binary doc values / numeric doc values) are > stored with sequence of document id. Sorted numeric doc values just means if > a document has multiple values, the values will be sorted for same document, > but for different documents, the value is still ordered by document id. Is > that true? > So, can doc values be persisted with order of values, not document id? This > should be fast in sort scenario that the values are pre-ordered instead of > scan/sort at runtime. --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
