Solr查询多个集合

Question

I have multiple collections with different fields in the schema, I would like to perform a search across multiple collections and perform default rank for results across all the collections .

Example - I have a document with 'mustang' word occurring 3 times in collection A and also 2 times in Collection B , then I would like the results to show both the documents with the document from collection A first and document from collection B as second result.

Answer 1

Scoring doesn't only take the number of occurrences into factor, so by default it'll also depend on the number of documents containing that term in the collection as well. If we're talking about a single term, you can sort by the tf function or something like that - for more complex queries, using collection wide term frequencies may be the only option (but may be costly).

To create one common collection that queries both, use the CREATEALIAS command in the Collections API. The collections parameter takes a comma separated list of collections that is represented by the alias, allowing you to query both A and B through the alias C.