On Jul 24, 2008, at 9:48 AM, Fuad Efendi wrote:
Hi, It's unclear... found in schema.xml: omitNorms: (expert) set to true to omit the norms associated with this field (this disables length normalization and index-time boosting for the field, and saves some memory). Only full-text fields or fields that need an index-time boost need norms.termVectors: [false] set to true to store the term vector for a given field. When using MoreLikeThis, fields used for similarity should be stored forbest performance. Questions:omitNorms: do I need it for full-text fields even if I don't need index-time boosting? I don't want to boost text where keyword repeated several time. Is my understanding correct?
I'm not sure what you are asking Do you mean you don't want term frequency factored in or you don't want length normalization and document/field boosting factored in?
termVectors: do I need it for MoreLikeThis only?
They can help speed up MLT, but are not required. If they are not available, than MLT has to re-analyze the field.
What are memory requirements for Lucene caches warming up if I use term vectors and norms?
I don't believe Term Vectors are cached anywhere, other than via the OS. I'd have to go dig around for norms info, or maybe someone else can chime in.
-Grant
