lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Los Morales" <morales...@hotmail.com>
Subject Re: lucene newbie question
Date Mon, 02 Oct 2006 18:46:45 GMT
Hi Erik,

Thanks for the response.

>Consider the index in the back of a book.  You could tear that out  and 
>still use it to tell what page something is on, but you have no  actual 
>content in hand.
So, I guess what I'm having a hard time trying to figure out is, what's the 
point of having an index when you can't search/retrieve the contents of a 
field in the index since it is not stored?  Isn't the whole point of having 
an index is to be able to search and retrieve the contents efficiently?

Basically I'm not sure the points of UnIndexed and UnStored fields types.  
Say I use a field type "unindexed" for my SSN.  I know its stored in the 
index but how am I suppose to retrieve it?
As for the unstored, its like the scenario I described above... I see the 
fields in the index but I won't be able to search/retrieve it since I don't 
have the contents.  The "text" field type makes sense to me (with data being 
a String), as well as the type "keyword".

Is there a scenario or scenarios you can describe where Unindexed/Unstored 
will be useful?  Thanks in advanced!

-los


>From: Erik Hatcher <erik@ehatchersolutions.com>
>Reply-To: java-user@lucene.apache.org
>To: java-user@lucene.apache.org
>Subject: Re: lucene newbie question
>Date: Mon, 2 Oct 2006 14:12:25 -0400
>
>
>On Oct 2, 2006, at 2:08 PM, Los Morales wrote:
>>I'm new to Lucene and IR in general.  I'm a bit confused on the  concept 
>>of fields.  From what I've read, a field does not have to  be indexed but 
>>its value can be stored in an index.  Likewise a  field can be indexed but 
>>its value is not stored in an index.  Now  how can a field be searchable 
>>when its value is not stored in the  index and vice-versa?  Again, I'm new 
>>to the Index/Search  paradigm.  Thanks in advanced.
>
>Consider the index in the back of a book.  You could tear that out  and 
>still use it to tell what page something is on, but you have no  actual 
>content in hand.  When a field is tokenized (and therefore  implicitly 
>indexed), it is run through the specified Analyzer and the  terms emitted 
>are indexed, but the original text may or may not also  be stored in the 
>index.
>
>Make sense?
>
>	Erik
>
>
>---------------------------------------------------------------------
>To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>For additional commands, e-mail: java-user-help@lucene.apache.org
>

_________________________________________________________________
Be seen and heard with Windows Live Messenger and Microsoft LifeCams 
http://clk.atdmt.com/MSN/go/msnnkwme0020000001msn/direct/01/?href=http://www.microsoft.com/hardware/digitalcommunication/default.mspx?locale=en-us&source=hmtagline


---------------------------------------------------------------------
To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
For additional commands, e-mail: java-user-help@lucene.apache.org


Mime
View raw message