Re: Faceted Search using Lucene

[Michael McCandless]

There is no such thing as final code -- code is alive and is always  
changing ;)

It looks good to me.

Though one trivial thing is: I would move the code in the try clause  
up to and including the multiSearcher=get() out above the try.  I  
always attempt to "shrink wrap" what's inside a try clause to the  
minimum that needs to be there.  Ie, your code that creates a query,  
finds the right sort & filter to use, etc, can all happen outside the  
try, because you have not yet acquired the multiSearcher.

If you do that, you also don't need the null check in the finally  
clause, because multiSearcher must be non-null on entering the try.

Mike

Amin Mohammed-Coleman wrote:

Hi there
Good morning!  Here is the final search code:

public Summary[] search(final SearchRequest searchRequest)
throwsSearchExecutionException {

final String searchTerm = searchRequest.getSearchTerm();

if (StringUtils.isBlank(searchTerm)) {

throw new SearchExecutionException("Search string cannot be empty.  
There
will be too many results to process.");

}

List<Summary> summaryList = new ArrayList<Summary>();

StopWatch stopWatch = new StopWatch("searchStopWatch");

stopWatch.start();

MultiSearcher multiSearcher = null;

try {

LOGGER.debug("Ensuring all index readers are up to date...");

maybeReopen();

Query query = queryParser.parse(searchTerm);

LOGGER.debug("Search Term '" + searchTerm +"' ----> Lucene Query '" +
query.toString() +"'");

Sort sort = null;

sort = applySortIfApplicable(searchRequest);

Filter[] filters =applyFiltersIfApplicable(searchRequest);

ChainedFilter chainedFilter = null;

if (filters != null) {

chainedFilter = new ChainedFilter(filters, ChainedFilter.OR);

}

multiSearcher = get();

TopDocs topDocs = multiSearcher.search(query,chainedFilter ,100,sort);

ScoreDoc[] scoreDocs = topDocs.scoreDocs;

LOGGER.debug("total number of hits for [" + query.toString() + " ] =  
"+topDocs.
totalHits);

for (ScoreDoc scoreDoc : scoreDocs) {

final Document doc = multiSearcher.doc(scoreDoc.doc);

float score = scoreDoc.score;

final BaseDocument baseDocument = new BaseDocument(doc, score);

Summary documentSummary = new DocumentSummaryImpl(baseDocument);

summaryList.add(documentSummary);

}

} catch (Exception e) {

throw new IllegalStateException(e);

} finally {

if (multiSearcher != null) {

release(multiSearcher);

}

}

stopWatch.stop();

LOGGER.debug("total time taken for document seach: " +
stopWatch.getTotalTimeMillis() + " ms");

return summaryList.toArray(new Summary[] {});

}



I hope this makes sense...thanks again!


Cheers

Amin



On Sun, Mar 1, 2009 at 8:09 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


You're calling get() too many times.  For every call to get() you  
must
match with a call to release().

So, once at the front of your search method you should:

MultiSearcher searcher = get();

then use that searcher to do searching, retrieve docs, etc.

Then in the finally clause, pass that searcher to release.

So, only one call to get() and one matching call to release().

Mike

Amin Mohammed-Coleman wrote:

Hi
The searchers are injected into the class via Spring.  So when a  
client
calls the class it is fully configured with a list of index  
searchers.
However I have removed this list and instead injecting a list of
directories which are passed to the DocumentSearchManager.
DocumentSearchManager is SearchManager (should've mentioned that  
earlier).
So finally I have modified by release code to do the following:

private void release(MultiSearcher multiSeacher) throws Exception {

IndexSearcher[] indexSearchers = (IndexSearcher[])
multiSeacher.getSearchables();

for(int i =0 ; i < indexSearchers.length;i++) {

documentSearcherManagers[i].release(indexSearchers[i]);

}

}


and it's use looks like this:


public Summary[] search(final SearchRequest searchRequest)
throwsSearchExecutionException {

final String searchTerm = searchRequest.getSearchTerm();

if (StringUtils.isBlank(searchTerm)) {

throw new SearchExecutionException("Search string cannot be empty.  
There
will be too many results to process.");

}

List<Summary> summaryList = new ArrayList<Summary>();

StopWatch stopWatch = new StopWatch("searchStopWatch");

stopWatch.start();

List<IndexSearcher> indexSearchers = new ArrayList<IndexSearcher>();

try {

LOGGER.debug("Ensuring all index readers are up to date...");

maybeReopen();

LOGGER.debug("All Index Searchers are up to date. No of index  
searchers '"
+
indexSearchers.size() +"'");

Query query = queryParser.parse(searchTerm);

LOGGER.debug("Search Term '" + searchTerm +"' ----> Lucene Query  
'" +
query.toString() +"'");

Sort sort = null;

sort = applySortIfApplicable(searchRequest);

Filter[] filters =applyFiltersIfApplicable(searchRequest);

ChainedFilter chainedFilter = null;

if (filters != null) {

chainedFilter = new ChainedFilter(filters, ChainedFilter.OR);

}

TopDocs topDocs = get().search(query,chainedFilter ,100,sort);

ScoreDoc[] scoreDocs = topDocs.scoreDocs;

LOGGER.debug("total number of hits for [" + query.toString() + " ] =
"+topDocs.
totalHits);

for (ScoreDoc scoreDoc : scoreDocs) {

final Document doc = get().doc(scoreDoc.doc);

float score = scoreDoc.score;

final BaseDocument baseDocument = new BaseDocument(doc, score);

Summary documentSummary = new DocumentSummaryImpl(baseDocument);

summaryList.add(documentSummary);

}

} catch (Exception e) {

throw new IllegalStateException(e);

} finally {

release(get());

}

stopWatch.stop();

LOGGER.debug("total time taken for document seach: " +
stopWatch.getTotalTimeMillis() + " ms");

return summaryList.toArray(new Summary[] {});

}


So the final post construct constructs the DocumentSearchMangers  
with the
list of directories..looking like this


@PostConstruct

public void initialiseDocumentSearcher() {

PerFieldAnalyzerWrapper analyzerWrapper = new  
PerFieldAnalyzerWrapper(
analyzer);

analyzerWrapper.addAnalyzer(FieldNameEnum.TYPE.getDescription(),
newKeywordAnalyzer());

queryParser =
newMultiFieldQueryParser(FieldNameEnum.fieldNameDescriptions(),
analyzerWrapper);

try {

LOGGER.debug("Initialising multi searcher ....");

documentSearcherManagers = new
DocumentSearcherManager[directories.size()];

for (int i = 0; i < directories.size() ;i++) {

Directory directory = directories.get(i);

DocumentSearcherManager documentSearcherManager =
newDocumentSearcherManager(directory);

documentSearcherManagers[i]=documentSearcherManager;

}

LOGGER.debug("multi searcher initialised");

} catch (IOException e) {

throw new IllegalStateException(e);

}

}



Cheers

Amin



On Sun, Mar 1, 2009 at 6:15 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


I don't understand where searchers comes from, prior to
initializeDocumentSearcher?  You should, instead, simply create the
SearcherManager (from your Directory instances).  You don't need  
any
searchers during initialize.

Is DocumentSearcherManager the same as SearcherManager (just  
renamed)?

The release method is wrong -- you're calling .get() and then
immediately release.  Instead, you should step through the  
searchers
from your MultiSearcher and release them to each SearcherManager.

You should call your release() in a finally clause.

Mike

Amin Mohammed-Coleman wrote:

Sorry...i'm getting slightly confused.

I have a PostConstruct which is where I should create an array of
SearchManagers (per indexSeacher).  From there I initialise the
multisearcher using the get().  After which I need to call  
maybeReopen
for
each IndexSearcher.  So I'll do the following:

@PostConstruct

public void initialiseDocumentSearcher() {

PerFieldAnalyzerWrapper analyzerWrapper = new  
PerFieldAnalyzerWrapper(
analyzer);

analyzerWrapper.addAnalyzer(FieldNameEnum.TYPE.getDescription(),
newKeywordAnalyzer());

queryParser =
newMultiFieldQueryParser(FieldNameEnum.fieldNameDescriptions(),
analyzerWrapper);

try {

LOGGER.debug("Initialising multi searcher ....");

documentSearcherManagers = new
DocumentSearcherManager[searchers.size()];

for (int i = 0; i < searchers.size() ;i++) {

IndexSearcher indexSearcher = searchers.get(i);

Directory directory = indexSearcher.getIndexReader().directory();

DocumentSearcherManager documentSearcherManager =
newDocumentSearcherManager(directory);

documentSearcherManagers[i]=documentSearcherManager;

}

LOGGER.debug("multi searcher initialised");

} catch (IOException e) {

throw new IllegalStateException(e);

}

}


This initialises search managers.  I then have methods:


private void maybeReopen() throws Exception {

LOGGER.debug("Initiating reopening of index readers...");

for (DocumentSearcherManager documentSearcherManager :
documentSearcherManagers) {

documentSearcherManager.maybeReopen();

}

}



private void release() throws Exception {

for (DocumentSearcherManager documentSearcherManager :
documentSearcherManagers) {

documentSearcherManager.release(documentSearcherManager.get());

}

}


private MultiSearcher get() {

List<IndexSearcher> listOfIndexSeachers = new
ArrayList<IndexSearcher>();

for (DocumentSearcherManager documentSearcherManager :
documentSearcherManagers) {

listOfIndexSeachers.add(documentSearcherManager.get());

}

try {

multiSearcher = new
MultiSearcher(listOfIndexSeachers.toArray(newIndexSearcher[] {}));

} catch (IOException e) {

throw new IllegalStateException(e);

}

return multiSearcher;

}


These methods are used in the following manner in the search code:


public Summary[] search(final SearchRequest searchRequest)
throwsSearchExecutionException {

final String searchTerm = searchRequest.getSearchTerm();

if (StringUtils.isBlank(searchTerm)) {

throw new SearchExecutionException("Search string cannot be  
empty. There
will be too many results to process.");

}

List<Summary> summaryList = new ArrayList<Summary>();

StopWatch stopWatch = new StopWatch("searchStopWatch");

stopWatch.start();

List<IndexSearcher> indexSearchers = new  
ArrayList<IndexSearcher>();

try {

LOGGER.debug("Ensuring all index readers are up to date...");

maybeReopen();

LOGGER.debug("All Index Searchers are up to date. No of index  
searchers
'"
+
indexSearchers.size() +"'");

Query query = queryParser.parse(searchTerm);

LOGGER.debug("Search Term '" + searchTerm +"' ----> Lucene Query  
'" +
query.toString() +"'");

Sort sort = null;

sort = applySortIfApplicable(searchRequest);

Filter[] filters =applyFiltersIfApplicable(searchRequest);

ChainedFilter chainedFilter = null;

if (filters != null) {

chainedFilter = new ChainedFilter(filters, ChainedFilter.OR);

}

TopDocs topDocs = get().search(query,chainedFilter ,100,sort);

ScoreDoc[] scoreDocs = topDocs.scoreDocs;

LOGGER.debug("total number of hits for [" + query.toString() +  
" ] =
"+topDocs.
totalHits);

for (ScoreDoc scoreDoc : scoreDocs) {

final Document doc = get().doc(scoreDoc.doc);

float score = scoreDoc.score;

final BaseDocument baseDocument = new BaseDocument(doc, score);

Summary documentSummary = new DocumentSummaryImpl(baseDocument);

summaryList.add(documentSummary);

}

release();

} catch (Exception e) {

throw new IllegalStateException(e);

}

stopWatch.stop();

LOGGER.debug("total time taken for document seach: " +
stopWatch.getTotalTimeMillis() + " ms");

return summaryList.toArray(new Summary[] {});

}


Does this look better?  Again..I really really appreciate your  
help!


On Sun, Mar 1, 2009 at 4:18 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


This is not quite right -- you should only create  
SearcherManager once
(per Direcotry) at startup/app load, not with every search  
request.

And I don't see release -- it must call SearcherManager.release  
of
each of the IndexSearchers previously returned from get().

Mike

Amin Mohammed-Coleman wrote:

Hi

Thanks again for helping on a Sunday!

I have now modified my maybeOpen() to do the following:

private void maybeReopen() throws Exception {

LOGGER.debug("Initiating reopening of index readers...");

IndexSearcher[] indexSearchers = (IndexSearcher[]) multiSearcher
.getSearchables();

for (IndexSearcher indexSearcher : indexSearchers) {

IndexReader indexReader = indexSearcher.getIndexReader();

SearcherManager documentSearcherManager = new
SearcherManager(indexReader.directory());

documentSearcherManager.maybeReopen();

}

}


And get() to:


private synchronized MultiSearcher get() {

IndexSearcher[] indexSearchers = (IndexSearcher[]) multiSearcher
.getSearchables();

List<IndexSearcher>  indexSearchersList = new
ArrayList<IndexSearcher>();

for (IndexSearcher indexSearcher : indexSearchers) {

IndexReader indexReader = indexSearcher.getIndexReader();

SearcherManager documentSearcherManager = null;

try {

documentSearcherManager = new
SearcherManager(indexReader.directory());

} catch (IOException e) {

throw new IllegalStateException(e);

}

indexSearchersList.add(documentSearcherManager.get());

}

try {

multiSearcher = new
MultiSearcher(indexSearchersList.toArray(newIndexSearcher[]  
{}));

} catch (IOException e) {

throw new IllegalStateException(e);

}

return multiSearcher;

}



This makes all my test pass.  I am using the SearchManager  
that you
recommended.  Does this look ok?


On Sun, Mar 1, 2009 at 2:38 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:

Your maybeReopen has an excess incRef().


I'm not sure how you open the searchers in the first place?   
The list
starts as empty, and nothing populates it?

When you do the initial population, you need an incRef.

I think you're hitting IllegalStateException because  
maybeReopen is
closing a reader before get() can get it (since they  
synchronize on
different objects).

I'd recommend switching to the SearcherManager class.   
Instantiate
one
for each of your searchers.  On each search request, go  
through them
and call maybeReopen(), and then call get() and gather each
IndexSearcher instance into a new array.  Then, make a new
MultiSearcher (opposite of what I said before): while that  
creates a
small amount of garbage, it'll keep your code simpler (good
tradeoff).

Mike

Amin Mohammed-Coleman wrote:

sorrry I added


release(multiSearcher);


instead of multiSearcher.close();

On Sun, Mar 1, 2009 at 2:17 PM, Amin Mohammed-Coleman <
ami...@gmail.com

wrote:



Hi

I've now done the following:


public Summary[] search(final SearchRequest searchRequest)
throwsSearchExecutionException {

final String searchTerm = searchRequest.getSearchTerm();

if (StringUtils.isBlank(searchTerm)) {

throw new SearchExecutionException("Search string cannot be  
empty.
There
will be too many results to process.");

}

List<Summary> summaryList = new ArrayList<Summary>();

StopWatch stopWatch = new StopWatch("searchStopWatch");

stopWatch.start();

List<IndexSearcher> indexSearchers = new
ArrayList<IndexSearcher>();

try {

LOGGER.debug("Ensuring all index readers are up to date...");

maybeReopen();

LOGGER.debug("All Index Searchers are up to date. No of index
searchers
'"+ indexSearchers.size() +
"'");

Query query = queryParser.parse(searchTerm);

LOGGER.debug("Search Term '" + searchTerm +"' ----> Lucene  
Query '"
+
query.toString() +"'");

Sort sort = null;

sort = applySortIfApplicable(searchRequest);

Filter[] filters =applyFiltersIfApplicable(searchRequest);

ChainedFilter chainedFilter = null;

if (filters != null) {

chainedFilter = new ChainedFilter(filters, ChainedFilter.OR);

}

TopDocs topDocs = get().search(query,chainedFilter , 
100,sort);

ScoreDoc[] scoreDocs = topDocs.scoreDocs;

LOGGER.debug("total number of hits for [" +  
query.toString() + " ]
=
"+topDocs.
totalHits);

for (ScoreDoc scoreDoc : scoreDocs) {

final Document doc = multiSearcher.doc(scoreDoc.doc);

float score = scoreDoc.score;

final BaseDocument baseDocument = new BaseDocument(doc,  
score);

Summary documentSummary = new  
DocumentSummaryImpl(baseDocument);

summaryList.add(documentSummary);

}

multiSearcher.close();

} catch (Exception e) {

throw new IllegalStateException(e);

}

stopWatch.stop();

LOGGER.debug("total time taken for document seach: " +
stopWatch.getTotalTimeMillis() + " ms");

return summaryList.toArray(new Summary[] {});

}


And have the following methods:

@PostConstruct

public void initialiseQueryParser() {

PerFieldAnalyzerWrapper analyzerWrapper = new
PerFieldAnalyzerWrapper(
analyzer);

analyzerWrapper 
.addAnalyzer(FieldNameEnum.TYPE.getDescription(),
newKeywordAnalyzer());

queryParser =
newMultiFieldQueryParser 
(FieldNameEnum.fieldNameDescriptions(),

analyzerWrapper);

try {

LOGGER.debug("Initialising multi searcher ....");

this.multiSearcher = new
MultiSearcher(searchers.toArray(newIndexSearcher[] {}));

LOGGER.debug("multi searcher initialised");

} catch (IOException e) {

throw new IllegalStateException(e);

}

}


Initialises mutltisearcher when this class is creared by  
spring.


private synchronized void swapMultiSearcher(MultiSearcher
newMultiSearcher)  {

try {

release(multiSearcher);

} catch (IOException e) {

throw new IllegalStateException(e);

}

multiSearcher = newMultiSearcher;

}

public void maybeReopen() throws IOException {

MultiSearcher newMultiSeacher = null;

boolean refreshMultiSeacher = false;

List<IndexSearcher> indexSearchers = new
ArrayList<IndexSearcher>();

synchronized (searchers) {

for (IndexSearcher indexSearcher: searchers) {

IndexReader reader = indexSearcher.getIndexReader();

reader.incRef();

Directory directory = reader.directory();

long currentVersion = reader.getVersion();

if (IndexReader.getCurrentVersion(directory) !=  
currentVersion) {

IndexReader newReader =  
indexSearcher.getIndexReader().reopen();

if (newReader != reader) {

reader.decRef();

refreshMultiSeacher = true;

}

reader = newReader;

IndexSearcher newSearcher = new IndexSearcher(newReader);

indexSearchers.add(newSearcher);

}

}

}



if (refreshMultiSeacher) {

newMultiSeacher = new
MultiSearcher(indexSearchers.toArray(newIndexSearcher[] {}));

warm(newMultiSeacher);

swapMultiSearcher(newMultiSeacher);

}



}


private void warm(MultiSearcher newMultiSeacher) {

}



private synchronized MultiSearcher get() {

for (IndexSearcher indexSearcher: searchers) {

indexSearcher.getIndexReader().incRef();

}

return multiSearcher;

}

private synchronized void release(MultiSearcher  
multiSearcher)
throwsIOException {

for (IndexSearcher indexSearcher: searchers) {

indexSearcher.getIndexReader().decRef();

}

}


However I am now getting


java.lang.IllegalStateException:
org.apache.lucene.store.AlreadyClosedException: this  
IndexReader is
closed


on the call:


private synchronized MultiSearcher get() {

for (IndexSearcher indexSearcher: searchers) {

indexSearcher.getIndexReader().incRef();

}

return multiSearcher;

}


I'm doing something wrong ..obviously..not sure where  
though..


Cheers


On Sun, Mar 1, 2009 at 1:36 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


I was wondering the same thing ;)


It's best to call this method from a single BG "warming"  
thread,
in
which
case it would not need its own synchronization.

But, to be safe, I'll add internal synchronization to it.   
You
can't
simply put synchronized in front of the method, since you  
don't
want
this to
block searching.


Mike

Amin Mohammed-Coleman wrote:

just a quick point:

public void maybeReopen() throws IOException  
{                 //D

long currentVersion =
currentSearcher.getIndexReader().getVersion();
if (IndexReader.getCurrentVersion(dir) != currentVersion) {
IndexReader newReader =
currentSearcher.getIndexReader().reopen();
assert newReader != currentSearcher.getIndexReader();
IndexSearcher newSearcher = new IndexSearcher(newReader);
warm(newSearcher);
swapSearcher(newSearcher);
}
}

should the above be synchronised?

On Sun, Mar 1, 2009 at 1:25 PM, Amin Mohammed-Coleman <
ami...@gmail.com

wrote:



thanks.  i will rewrite..in between giving my baby her  
feed and

playing

with the other child and my wife who wants me to do  
several other

things!



On Sun, Mar 1, 2009 at 1:20 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


Amin Mohammed-Coleman wrote:


Hi

Thanks for your input.  I would like to have a go at  
doing this

myself

first, Solr may be an option.

* You are creating a new Analyzer & QueryParser every  
time,
also
creating unnecessary garbage; instead, they should be  
created
once
& reused.

-- I can moved the code out so that it is only created  
once
and
reused.


* You always make a new IndexSearcher and a new  
MultiSearcher
even
when nothing has changed.  This just generates  
unnecessary
garbage
which GC then must sweep up.

-- This was something I thought about.  I could move  
it out so
that
it's
created once.  However I presume inside my code i need  
to
check
whether
the
indexreaders are update to date.  This needs to be
synchronized
as
well I
guess(?)


Yes you should synchronize the check for whether the
IndexReader
is

current.


* I don't see any synchronization -- it looks like two  
search

requests are allowed into this method at the same  
time?  Which
is

dangerous... eg both (or, more) will wastefully reopen  
the

readers.
--  So i need to extract the logic for reopening and  
provide a
synchronisation mechanism.


Yes.



Ok.  So I have some work to do.  I'll refactor the code  
and see
if
I
can

get

inline to your recommendations.



On Sun, Mar 1, 2009 at 12:11 PM, Michael McCandless <
luc...@mikemccandless.com> wrote:


On a quick look, I think there are a few problems with  
the
code:


* I don't see any synchronization -- it looks like two  
search

requests are allowed into this method at the same time?
Which
is
dangerous... eg both (or, more) will wastefully  
reopen the
readers.

* You are over-incRef'ing (the reader.incRef inside  
the loop)
--
I
don't see a corresponding decRef.

* You reopen and warm your searchers "live" (vs with BG
thread);
meaning the unlucky search request that hits a reopen  
pays
the
cost.  This might be OK if the index is small enough  
that
reopening & warming takes very little time.  But if  
index
gets
large, making a random search pay that warming cost  
is not
nice
to
the end user.  It erodes their trust in you.

* You always make a new IndexSearcher and a new  
MultiSearcher
even
when nothing has changed.  This just generates  
unnecessary
garbage
which GC then must sweep up.

* You are creating a new Analyzer & QueryParser every  
time,
also
creating unnecessary garbage; instead, they should be  
created
once
& reused.

You should consider simply using Solr -- it handles  
all this
logic
for
you and has been well debugged with time...

Mike

Amin Mohammed-Coleman wrote:

The reason for the indexreader.reopen is because I  
have a
webapp
which

enables users to upload files and then search for the
documents.
If

I

don't
reopen i'm concerned that the facet hit counter  
won't be
updated.

On Tue, Feb 24, 2009 at 8:32 PM, Amin Mohammed- 
Coleman <
ami...@gmail.com

wrote:



Hi


I have been able to get the code working for my  
scenario,
however
I

have

a
question and I was wondering if I could get some  
help.  I
have
a
list
of
IndexSearchers which are used in a MultiSearcher  
class.  I
use
the
indexsearchers to get each indexreader and put them  
into a
MultiIndexReader.

IndexReader[] readers = new
IndexReader[searchables.length];

for (int i =0 ; i < searchables.length;i++) {

IndexSearcher indexSearcher =
(IndexSearcher)searchables[i];

readers[i] = indexSearcher.getIndexReader();

IndexReader newReader = readers[i].reopen();

if (newReader != readers[i]) {

readers[i].close();

}

readers[i] = newReader;



}

multiReader = new MultiReader(readers);

OpenBitSetFacetHitCounter facetHitCounter =
newOpenBitSetFacetHitCounter();

IndexSearcher indexSearcher = new
IndexSearcher(multiReader);


I then use the indexseacher to do the facet stuff.   
I end
the
code
with
closing the multireader.  This is causing problems in
another
method
where I
do some other search as the indexreaders are  
closed.  Is it
ok
to
not
close
the multiindexreader or should I do some additional  
checks
in
the
other
method to see if the indexreader is closed?



Cheers


P.S. Hope that made sense...!


On Mon, Feb 23, 2009 at 7:20 AM, Amin Mohammed- 
Coleman <
ami...@gmail.com

wrote:



Hi



Thanks just what I needed!


Cheers
Amin


On 22 Feb 2009, at 16:11, Marcelo Ochoa <
marcelo.oc...@gmail.com>
wrote:

Hi Amin:

Please take a look a this blog post:









http://sujitpal.blogspot.com/2007/04/lucene-search-within-search-with.html
Best regards, Marcelo.

On Sun, Feb 22, 2009 at 1:18 PM, Amin Mohammed- 
Coleman <
ami...@gmail.com>
wrote:

Hi


Sorry to re send this email but I was wondering  
if I
could
get

some

advice
on this.

Cheers

Amin

On 16 Feb 2009, at 20:37, Amin Mohammed-Coleman <
ami...@gmail.com>
wrote:

Hi


I am looking at building a faceted search using  
Lucene.
I
know

that

Solr
comes with this built in, however I would like  
to try
this
by
myself
(something to add to my CV!).  I have been  
looking
around
and
I
found
that
you can use the IndexReader and use  
TermVectors.  This
looks
ok
but
I'm
not
sure how to filter the results so that a  
particular
user
can
only
see
a
subset of results.  The next option I was  
looking at
was
something
like

Term term1 = new Term("brand", "ford");
Term term2 = new Term("brand", "vw");
Term[] termsArray = new Term[] { term1,  
term2 };un
int[] docFreqs =  
indexSearcher.docFreqs(termsArray);

The only problem here is that I have to provide  
the
brand
type
each
time a
new brand is created.  Again I'm not sure how I  
can
filter
the
results
here.
It may be that I'm using the wrong api methods  
to do
this.

I would be grateful if I could get some advice  
on this.


Cheers
Amin

P.S.  I am basically trying to do something that
displays
the
following

Personal Contact (23) Business Contact (45) and  
so on..










--


Marcelo F. Ochoa

http://marceloochoa.blogspot.com/
http://marcelo.ochoa.googlepages.com/home
______________
Want to integrate Lucene and Oracle?








http://marceloochoa.blogspot.com/2007/09/running-lucene-inside-your-oracle-jvm.html
Is Oracle 11g REST ready?






http://marceloochoa.blogspot.com/2008/02/is-oracle-11g-rest-ready.html







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