lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tom.Hic...@USPTO.GOV
Subject RE: Wildcard workaround
Date Wed, 04 Jun 2003 17:04:15 GMT
I think BRS was probably using the reversed index trick long before Oracle,
so hopefully Oracle has no rights to it.  I'm not sure it meets the criteria
for non-obvious anyway.  We use BRS here for trademark searching and make
extensive use of the reversed index capability for left-hand wild card


-----Original Message-----
From: []
Sent: Thursday, May 29, 2003 8:58 PM
Subject: Re: Wildcard workaround

On Wednesday 28 May 2003 05:43, David Medinets wrote:
> ----- Original Message -----
> From: "Andrei Melis" <>
> > As far as I have understood, lucene does not allow search queries
> > starting with wildcards. I have a file database indexed by content
> > and also by filename. It would be nice if the user could perform a
> > usual search like "*.ext".
> Does anyone know if Oracle patented the technique that they use for *ext
> searching in the Oracle Text product. If not, I'm sure the technique can
> borrowed.
> On the other hand, the slow technique of comparing each term to *.ext can
> certainly be implemented with a minimum of effort, I think.

[apologies if somebody else already pointed this out... I missed some mails
the list from yesterday]

One of the most interesting solutions somebody posted earlier, was to use
2 indexes; one for 'normal' searches, with normal analyzer etc, and second
one that uses reversed words; ie. analyzer reverses words tokenized by
standard analyzer. This second index would then allow for searches
to do prefix match, in this case query would be something like


This would work efficiently, although pretty much double the size of index
content that has to be prefix-searchable. Still, this solution somehow 
appeals to my hacker side. :-)

In this specific case, though, what others have suggested (add file prefix
separate field to search on), is probably more practical.

-+ Tatu +-

To unsubscribe, e-mail:
For additional commands, e-mail:

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message