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https://issues.apache.org/jira/browse/LUCENE-7416?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15437246#comment-15437246
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Uwe Schindler edited comment on LUCENE-7416 at 8/25/16 5:09 PM:
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bq. I'm not sure about these rules in particular, but I know some existing
rules are useful, such as the one that rewrites to a CSQ around the filters
when the single MUST clause is a MatchAllDocsQuery. I think one reason why this
happens is that apps have a fixed filter and then a configurable query that
depends on the user and that defaults to a MatchAllDocsQuery.
This was a huge issue for Solr where people used {{q=\*:\*}} as query and only
applied filter claused ({{fq}}), the common case for faceted navigation without
query.
Anyways, we can add another consition to the above set: If any MUST_NOT clause
is a MatchAllDocs() we can return MatchNoDocs, too :-)
was (Author: thetaphi):
bq. I'm not sure about these rules in particular, but I know some existing
rules are useful, such as the one that rewrites to a CSQ around the filters
when the single MUST clause is a MatchAllDocsQuery. I think one reason why this
happens is that apps have a fixed filter and then a configurable query that
depends on the user and that defaults to a MatchAllDocsQuery.
This was a huge issue for Solr where people used {{q=*:*}} as query and only
applied filter claused ({{fq}}), the common case for faceted navigation without
query.
Anyways, we can add another consition to the above set: If any MUST_NOT clause
is a MatchAllDocs() we can return MatchNoDocs, too :-)
> BooleanQuery rewrite optimizations
> ----------------------------------
>
> Key: LUCENE-7416
> URL: https://issues.apache.org/jira/browse/LUCENE-7416
> Project: Lucene - Core
> Issue Type: Improvement
> Components: core/search
> Affects Versions: master (7.0)
> Reporter: Spyros Kapnissis
> Priority: Minor
> Fix For: master (7.0), 6.3
>
> Attachments: LUCENE-7146-simplific1.patch,
> LUCENE-7146-simplific1.patch, LUCENE-7146.patch
>
>
> A couple of BooleanQuery rewrites / optimizations.
> First, as discussed on the user group, a BooleanQuery with a query that is
> both a SHOULD and a FILTER can be rewritten as a single MUST query, but care
> must be taken to decrement minShouldMatch by 1.
> Another case is if a query is both required (MUST or FILTER) and MUST_NOT at
> the same time, it can be converted to a MatchNoDocsQuery (although I haven't
> discussed this yet so hopefully I'm not missing something!).
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