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Jordi Salvat i Alabart commented on LUCENE-3957: ------------------------------------------------ Wherever, but please increase exposure of this detail, for the sake of those who're coming in later. It's a VERY long and winded way between setting a $docBoost in a SolR dataSource transformer script and the current location of this information. Would be kind of acceptable if the value was held with a couple of decimal digits of precision, but the default (3-bit) implementation doesn't hold even ONE digit, making the behaviour really shocking -- specially since the boost value is not directly visible, but only through its impact on search scores. > Document precision requirements of setBoost calls > ------------------------------------------------- > > Key: LUCENE-3957 > URL: https://issues.apache.org/jira/browse/LUCENE-3957 > Project: Lucene - Java > Issue Type: Improvement > Components: general/javadocs > Affects Versions: 3.5 > Reporter: Jordi Salvat i Alabart > > The behaviour of index-time boosts seems pretty erratic (e.g. a boost of 8.0 > produces the exact same score as a boost of 9.0) until you become aware that > these factors end up encoded in a single byte, with a three-bit mantissa. > This consumed a whole day of research for us, and I still believe we were > lucky to spot it, given how deeply dug into the code & documentation this > information is. > I suggest adding a small note to the JavaDoc of setBoost methods in Document, > Fieldable, FieldInvertState, and possibly AbstractField, Field, and > NumericField. > Suggested text: > "Note that all index-time boost values end up encoded using > Similarity.encodeNormValue, with a 3-bit mantissa -- so differences in the > boost value of less than 25% may easily be rounded away." -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org