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https://issues.apache.org/jira/browse/LUCENE-1606?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12780801#action_12780801
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Uwe Schindler edited comment on LUCENE-1606 at 11/20/09 10:45 PM:
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bq. Uwe, i looked at the WildcardTermEnum and it was easy to make it a
subclass, with no logic, just a ctor.
That was my idea!
bq. This is where all the logic really is anyway.
We should simply add a test for this method and everything else is the
WildCardEnum. The good thing of subclassing it is, that one has a more
performat class if it uses common prefixes and so on than the version we
currently have. The wildcardEquals method must stay, but it is not used, so
explicitely mark it as "dead code".
The good thing: the method is final (this is what I see from yor fragment) - so
nobody was able to override it to change the behaviour of the enum, so nothing
can break.
I would go this way.
was (Author: thetaphi):
bq. Uwe, i looked at the WildcardTermEnum and it was easy to make it a
subclass, with no logic, just a ctor.
That was my idea!
bq. This is where all the logic really is anyway.
We should simply add a test for this method and everything else is the
WildCardEnum. The good thing of subclassing it is, that one has a more
performat class if it uses common prefixes and so on than the version we
currently have. The wildcardEquals method must stay, but it is not used, so
explicitely mark it as "dead code".
I would go this way.
> Automaton Query/Filter (scalable regex)
> ---------------------------------------
>
> Key: LUCENE-1606
> URL: https://issues.apache.org/jira/browse/LUCENE-1606
> Project: Lucene - Java
> Issue Type: New Feature
> Components: contrib/*
> Reporter: Robert Muir
> Assignee: Robert Muir
> Priority: Minor
> Fix For: 3.1
>
> Attachments: automaton.patch, automatonMultiQuery.patch,
> automatonmultiqueryfuzzy.patch, automatonMultiQuerySmart.patch,
> automatonWithWildCard.patch, automatonWithWildCard2.patch, LUCENE-1606.patch,
> LUCENE-1606.patch, LUCENE-1606.patch, LUCENE-1606_nodep.patch
>
>
> Attached is a patch for an AutomatonQuery/Filter (name can change if its not
> suitable).
> Whereas the out-of-box contrib RegexQuery is nice, I have some very large
> indexes (100M+ unique tokens) where queries are quite slow, 2 minutes, etc.
> Additionally all of the existing RegexQuery implementations in Lucene are
> really slow if there is no constant prefix. This implementation does not
> depend upon constant prefix, and runs the same query in 640ms.
> Some use cases I envision:
> 1. lexicography/etc on large text corpora
> 2. looking for things such as urls where the prefix is not constant (http://
> or ftp://)
> The Filter uses the BRICS package (http://www.brics.dk/automaton/) to convert
> regular expressions into a DFA. Then, the filter "enumerates" terms in a
> special way, by using the underlying state machine. Here is my short
> description from the comments:
> The algorithm here is pretty basic. Enumerate terms but instead of a
> binary accept/reject do:
>
> 1. Look at the portion that is OK (did not enter a reject state in the
> DFA)
> 2. Generate the next possible String and seek to that.
> the Query simply wraps the filter with ConstantScoreQuery.
> I did not include the automaton.jar inside the patch but it can be downloaded
> from http://www.brics.dk/automaton/ and is BSD-licensed.
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