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From "geoff hendrey (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-472) Full Text Indexing / Full Text Search
Date Fri, 13 Mar 2009 19:34:50 GMT

    [ https://issues.apache.org/jira/browse/DERBY-472?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12681873#action_12681873
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geoff hendrey commented on DERBY-472:
-------------------------------------

as background on my interest in this, I just finished a three month project implementing search
with lucene on 1,950,000 documents. It works fantastically, but requires careful local specific
configuration.

Based on what I learned I would recommend a loose coupling in which a server can listen on
the wire for tx logs like the ones shipped to the asynch replication server. The server simply
receives the tx log and indexes the information in lucene. I could code the listener if you
have docs on the replication protocol.

> Full Text Indexing / Full Text Search
> -------------------------------------
>
>                 Key: DERBY-472
>                 URL: https://issues.apache.org/jira/browse/DERBY-472
>             Project: Derby
>          Issue Type: New Feature
>          Components: SQL
>    Affects Versions: 10.0.2.0
>         Environment: All environments
>            Reporter: Rick Hillegas
>
> Efficiently support full text search of string datatyped columns. Mag Gam raised this
issue on the user's mailing list on 24 July 2005; the email thread is titled 'Full Text Indexing'.
Mag wants to see something akin to the functionality in tsearch2 (http://www.sai.msu.su/~megera/postgres/gist/tsearch/V2/).
Dan points out that we may be able to re-use index building technology exposed by the apache
Lucene project (http://lucene.apache.org/).
> Presumably we want to build inverted indexes on all string datatyped columns: CHAR, VARCHAR,
LONG VARCHAR, CLOB,, and their national variants (when they are implemented). We should consider
the following additional issues when specifying this feature:
> 1) Do we also want to support text search on XML columns?
> 2) Which human languages do we support initially? Each language has its own rules for
lexing words and its own list of "noise" words which should not be indexed. Hopefully, we
can plug-in some existing packages of lexers and noise filters. We should encourage users
to donate additional lexers/fitlers.
> 3) The CREATE INDEX syntax (for these new inverted indexes)  should let us bind a lexing
human language to a string-datatyped column.
> 4) How do we express the search condition? For case-sensitive searches we can get away
with boolean expressions built out of standard LIKE clauses. However, in my opinion, case-sensitive
searches are an edge case. The more useful situation is a case-insensitive search. Can we
get away with introducing a non-standard function here or do we need to push a proposal through
the standards commitees? Even more useful and non-standard are fuzzy searches, which tolerate
bad spellers.

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