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Erick Erickson commented on SOLR-8220: -------------------------------------- Random thought that occurred to me before coffee, so be warned. The initial statement here is 'Many times a value will be both stored="true" and docValues="true" ', then there was a lot of discussion about efficiencies etc... Why are we trying to anticipate "the right thing to do"? It would be simpler to code something like: > If the field is stored=true, return the stored value (don't even need to look > whether DV is true or not). > If the field is stored=false and docValues=true, return the DV value. Now it's totally under the control of the user which path is chosen through the schema definition; we don't have to try to guess anything. No new syntax. Maybe with a new "best practice" or something. There would be a learning curve for users around using only docValues=true for efficiency and _not_ setting stored=true. Not quite sure what to do if the user defines both however, perhaps use the stored value? The thing one does lose is the ability to get 2 and 1.999999999999 from the _same_ field, so there would be the added burden on the user of having to have two fields, one stored-only one dv-only if that distinction was important. And in the "wild and crazy" department (and for a different ticket _entirely_) we could consider disallowing fields with both docValues=true and stored=true. Not advocating this last, just throwing out for discussion. Let me emphasize that I don't have any investment in doing things this way, and apologies for thinking of this so late in the game. > Read field from docValues for non stored fields > ----------------------------------------------- > > Key: SOLR-8220 > URL: https://issues.apache.org/jira/browse/SOLR-8220 > Project: Solr > Issue Type: Improvement > Reporter: Keith Laban > Attachments: SOLR-8220-ishan.patch, SOLR-8220-ishan.patch, > SOLR-8220-ishan.patch, SOLR-8220-ishan.patch, SOLR-8220.patch, > SOLR-8220.patch, SOLR-8220.patch, SOLR-8220.patch, SOLR-8220.patch, > SOLR-8220.patch, SOLR-8220.patch, SOLR-8220.patch > > > Many times a value will be both stored="true" and docValues="true" which > requires redundant data to be stored on disk. Since reading from docValues is > both efficient and a common practice (facets, analytics, streaming, etc), > reading values from docValues when a stored version of the field does not > exist would be a valuable disk usage optimization. > The only caveat with this that I can see would be for multiValued fields as > they would always be returned sorted in the docValues approach. I believe > this is a fair compromise. > I've done a rough implementation for this as a field transform, but I think > it should live closer to where stored fields are loaded in the > SolrIndexSearcher. > Two open questions/observations: > 1) There doesn't seem to be a standard way to read values for docValues, > facets, analytics, streaming, etc, all seem to be doing their own ways, > perhaps some of this logic should be centralized. > 2) What will the API behavior be? (Below is my proposed implementation) > Parameters for fl: > - fl="docValueField" > -- return field from docValue if the field is not stored and in docValues, > if the field is stored return it from stored fields > - fl="*" > -- return only stored fields > - fl="+" > -- return stored fields and docValue fields > 2a - would be easiest implementation and might be sufficient for a first > pass. 2b - is current behavior -- 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