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https://issues.apache.org/jira/browse/SOLR-758?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12801314#action_12801314
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David Smiley commented on SOLR-758:
-----------------------------------
If the use-case is unrestricted Lucene syntax w/ dismax then Enhanced Dismax is
the way to go. What I'm shooting for in this issue is a more extensible query
parser. E-Dismax is cool but it doesn't look particularly extensible.
For example, in an app I support, I use this patch to do several things:
1. check if appears to be using fancy Lucene syntax and if so then treat as
such.. but with dismax of course on non-fielded clauses via SOLR-756
2. If one clause then rewrite query to: clause *clause*^0.5 -- i.e.
search for clause and also include partial matches. For a small index I have
this is fine but I can use n-gram some day if I need to.
3. If multiple clauses then rewrite query to: clauseA clauseB clauseC
clauseC*^0.5 (clauseC is last clause).
What I'm hoping for is for Solr to offer better query parsing infrastructure so
that I can implement my parsing needs by re-using/plugging into as much as
already exists as possible. Committing SOLR-756 is one step there... but then
there's some useful capabilty in DismaxQParser like boost queries, boost
functions, q.alt. min-should-match is relatively re-usable since it stands
alone.
> Enhance DisMaxQParserPlugin to support full-Solr syntax and to support
> alternate escaping strategies.
> -----------------------------------------------------------------------------------------------------
>
> Key: SOLR-758
> URL: https://issues.apache.org/jira/browse/SOLR-758
> Project: Solr
> Issue Type: Improvement
> Components: search
> Affects Versions: 1.3
> Reporter: David Smiley
> Fix For: 1.5
>
> Attachments: AdvancedQParserPlugin.java, AdvancedQParserPlugin.java,
> DisMaxQParserPlugin.java, DisMaxQParserPlugin.java, UserQParser.java,
> UserQParser.java, UserQParser.java-umlauts.patch
>
>
> The DisMaxQParserPlugin has a variety of nice features; chief among them is
> that is uses the DisjunctionMaxQueryParser. However it imposes limitations
> on the syntax.
> I've enhanced the DisMax QParser plugin to use a pluggable query string
> re-writer (via subclass extension) instead of hard-coding the logic currently
> embedded within it (i.e. the escape nearly everything logic). Additionally,
> I've made this QParser have a notion of a "simple" syntax (the default) or
> non-simple in which case some of the logic in this QParser doesn't occur
> because it's irrelevant (phrase boosting and min-should-max in particular).
> As part of my work I significantly moved the code around to make it clearer
> and more extensible. I also chose to rename it to suggest it's role as a
> parser for user queries.
> Attachment to follow...
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