This is an automated email from the ASF dual-hosted git repository. dsmiley pushed a commit to branch SOLR-14166-docs in repository https://gitbox.apache.org/repos/asf/solr.git
commit a264165db4bd2173d259275a12d6090634dac28e Author: David Smiley <[email protected]> AuthorDate: Mon May 3 23:35:56 2021 -0400 SOLR-14166: ref guide docs --- solr/solr-ref-guide/src/common-query-parameters.adoc | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/solr/solr-ref-guide/src/common-query-parameters.adoc b/solr/solr-ref-guide/src/common-query-parameters.adoc index d14b899..6e88ff8 100644 --- a/solr/solr-ref-guide/src/common-query-parameters.adoc +++ b/solr/solr-ref-guide/src/common-query-parameters.adoc @@ -278,9 +278,12 @@ If you do not define the `wt` parameter in your queries, JSON will be returned a Solr caches the results of all queries and filter queries by default. To disable result caching, set the `cache=false` parameter. -You can also use the `cost` option to control the order in which non-cached filter queries are evaluated. This allows you to order less expensive non-cached filters before expensive non-cached filters. +You can also use the `cost` option to provide a hint as to the order in which non-cached filter queries are evaluated. +This allows you to order less expensive non-cached filters before expensive non-cached filters. +At the Lucene layer, this maps to `TwoPhaseIterator.matchCost` if the query has a TPI. -For very high cost filters, if `cache=false` and `cost>=100` and the query implements the `PostFilter` interface, a Collector will be requested from that query and used to filter documents after they have matched the main query and all other filter queries. There can be multiple post filters; they are also ordered by cost. +*Post Filters*: For very high cost filters, if `cache=false` _and_ `cost>=100`, _and_ the query implements the `PostFilter` interface, a Collector will be requested from that query and used to filter documents after they have matched the main query and all other filter queries. +There can be multiple post filters; they are also ordered by cost. For most queries the default behavior is `cost=0`, but some types of queries (such as `{!frange}`) default to `cost=100`, because they are most efficient when used as a `PostFilter`.
