Dennis Gove created SOLR-7707: --------------------------------- Summary: Add StreamExpression Support to RollupStream Key: SOLR-7707 URL: https://issues.apache.org/jira/browse/SOLR-7707 Project: Solr Issue Type: Improvement Components: SolrJ Reporter: Dennis Gove Priority: Minor
This ticket is to add Stream Expression support to the RollupStream as discussed in SOLR-7560. Proposed expression syntax for the RollupStream (copied from that ticket) {code} rollup( someStream(....), over="fieldA, fieldB, fieldC", min(fieldA), max(fieldA), min(fieldB), mean(fieldD), sum(fieldC) ) {code} This requires making the *Metric types Expressible but I think that ends up as a good thing. Would make it real easy to support other options on metrics like excluding outliers, for example find the sum of values within 3 standard deviations from the mean could be {code} sum(fieldC, limit=standardDev(3)) {code} (note, how that particular calculation could be implemented is left as an exercise for the reader, I'm just using it as an example of adding additional options on a relatively simple metric). Another option example is what to do with null values. For example, in some cases a null should not impact a mean but in others it should. You could express those as {code} mean(fieldA, replace(null, 0)) // replace null values with 0 thus leading to an impact on the mean mean(fieldA, includeNull="true") // nulls are counted in the denominator but nothing added to numerator mean(fieldA, includeNull="false") // nulls neither counted in denominator nor added to numerator mean(fieldA, replace(null, fieldB), includeNull="true") // if fieldA is null replace it with fieldB, include null fieldB in mean {code} so on and so forth. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org