Re: Zero hits for queries ending with a number
Extremely well said, Tatu! On Apr 3, 2004, at 11:24 AM, Tatu Saloranta wrote: On Saturday 03 April 2004 08:34, [EMAIL PROTECTED] wrote: On Saturday 03 April 2004 17:11, Erik Hatcher wrote: No objections that error messages and such could be made clearer. Patches welcome! Care to submit better error message handling in this case? Or perhaps allow lower-case "to"? I think the best would be if Lucene would simply have a setCaseSensitive(boolean). IMHO it's in any case a bad idea to make searches case-sensitive (per default). I'd have to disagree. I think that search engine core should not have to bother with details of character sets, such as lower-casing. Rules for lower/upper/initial/mixed case for all Unicode-languages are rather involved... and if you tried to do that, next thing would be whether accentuation and umlaut marks should matter or not (which is language dependant). That's why to me the natural way to go is to do direct comparison, ignoring case when executing queries. This does not prevent anyone from implementing such functionality (see below). I think architecture and design of Lucene core is delightfully simple. One can easily create case-independent functionality by using proper analyzers, and (for the most part), configuring QueryParser. I would agree, however, that QueryParser is "victim of its success"; it's too often used in situations where one really should create proper GUI that builds the query. Backend code can then mangle input as it sees fit, and build query objects. QueryParser is more natural for quick-n-dirty scenarios, where one just has to slap something together quickly, or if one only has textual interface to deal with. It's nice thing to have, but it has its limitations; there's no way to create one parser that's perfect for every use(r). What could be done would be to make sure all examples / demo web apps would implement case-insensitive indexing and searching, since that is often what is needed? -+ Tatu +- But, also, folks need to really step back and practice basic troubleshooting skills. I asked you if that string was what you passed to the QueryParser and you said yes, when in fact it was not. And you I forgot that I did lower-case it. I fact I even output it in it's original state but lower-case it just before I pass it to lucene. That lower-casing is what I would call a hack and hence it's no surprise that I forgot it :-) Timo - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Saturday 03 April 2004 08:34, [EMAIL PROTECTED] wrote: > On Saturday 03 April 2004 17:11, Erik Hatcher wrote: > > No objections that error messages and such could be made clearer. > > Patches welcome! Care to submit better error message handling in this > > case? Or perhaps allow lower-case "to"? > > I think the best would be if Lucene would simply have a > setCaseSensitive(boolean). > > IMHO it's in any case a bad idea to make searches case-sensitive (per > default). I'd have to disagree. I think that search engine core should not have to bother with details of character sets, such as lower-casing. Rules for lower/upper/initial/mixed case for all Unicode-languages are rather involved... and if you tried to do that, next thing would be whether accentuation and umlaut marks should matter or not (which is language dependant). That's why to me the natural way to go is to do direct comparison, ignoring case when executing queries. This does not prevent anyone from implementing such functionality (see below). I think architecture and design of Lucene core is delightfully simple. One can easily create case-independent functionality by using proper analyzers, and (for the most part), configuring QueryParser. I would agree, however, that QueryParser is "victim of its success"; it's too often used in situations where one really should create proper GUI that builds the query. Backend code can then mangle input as it sees fit, and build query objects. QueryParser is more natural for quick-n-dirty scenarios, where one just has to slap something together quickly, or if one only has textual interface to deal with. It's nice thing to have, but it has its limitations; there's no way to create one parser that's perfect for every use(r). What could be done would be to make sure all examples / demo web apps would implement case-insensitive indexing and searching, since that is often what is needed? -+ Tatu +- > > > But, also, folks need to really step back and practice basic > > troubleshooting skills. I asked you if that string was what you passed > > to the QueryParser and you said yes, when in fact it was not. And you > > I forgot that I did lower-case it. I fact I even output it in it's original > state but lower-case it just before I pass it to lucene. That lower-casing > is what I would call a hack and hence it's no surprise that I forgot it :-) > > Timo > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Apr 3, 2004, at 10:34 AM, [EMAIL PROTECTED] wrote: I forgot that I did lower-case it. I fact I even output it in it's original state but lower-case it just before I pass it to lucene. That lower-casing is what I would call a hack and hence it's no surprise that I forgot it :-) But why even lowercase? That is what an analyzer typically does anyway (look at the output from AnalysisDemo to see). Note that there are switches on QueryParser (and MultiFieldQueryParser is lacking in this respect, another reason not to use it) that does lowercase wildcard terms automatically: setLowercaseWildcardTerms(true). Wildcard terms are not analyzed by QueryParser, so this was added to account for it. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Saturday 03 April 2004 17:11, Erik Hatcher wrote: > No objections that error messages and such could be made clearer. > Patches welcome! Care to submit better error message handling in this > case? Or perhaps allow lower-case "to"? I think the best would be if Lucene would simply have a setCaseSensitive(boolean). IMHO it's in any case a bad idea to make searches case-sensitive (per default). > But, also, folks need to really step back and practice basic > troubleshooting skills. I asked you if that string was what you passed > to the QueryParser and you said yes, when in fact it was not. And you I forgot that I did lower-case it. I fact I even output it in it's original state but lower-case it just before I pass it to lucene. That lower-casing is what I would call a hack and hence it's no surprise that I forgot it :-) Timo - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Apr 3, 2004, at 9:59 AM, [EMAIL PROTECTED] wrote: On Saturday 03 April 2004 15:19, Erik Hatcher wrote: date:[20030101 TO 20030202] I found the/my bug. Since Lucene is case-sensitive, I do lower-case all queries for user's convenience. The ParseException is thrown because the "TO" becomes "to". Well, I really think Lucene needs to daff such stumbling blocks aside... No objections that error messages and such could be made clearer. Patches welcome! Care to submit better error message handling in this case? Or perhaps allow lower-case "to"? But, also, folks need to really step back and practice basic troubleshooting skills. I asked you if that string was what you passed to the QueryParser and you said yes, when in fact it was not. And you slowly fed more details of your scenario (MFQP, some German SnowballAnalyzer variant). Reduce the variables in the equation and narrow things down until it works and then incrementally add complexity. I cannot encourage folks enough to try some JUnit test-driven *learning* by exploring various scenarios. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Saturday 03 April 2004 15:19, Erik Hatcher wrote: > date:[20030101 TO 20030202] I found the/my bug. Since Lucene is case-sensitive, I do lower-case all queries for user's convenience. The ParseException is thrown because the "TO" becomes "to". Well, I really think Lucene needs to daff such stumbling blocks aside... - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
Ok, we're getting somewhere now. So, where is the exception you encountered when using this utility code?! (i.e. it didn't thrown an exception, so something is different in your usage in your code). I tried this: Query query = MultiFieldQueryParser.parse("date:[20030101 TO 20030202]", new String[] { "id", "title", "summary", "contents", "date" }, new GermanAnalyzer()); System.out.println("query = " + query.toString()); And it worked fine (only duplicated the query for each field). No exception at all. Of course I'm guessing on your analyzer since you didn't provide that detail (although it shouldn't matter in the exception you experienced). On Apr 3, 2004, at 6:06 AM, [EMAIL PROTECTED] wrote: SnowballAnalyzer("German2"): Analzying "http://www.yahoo.com/foo/bar.html"; org.apache.lucene.analysis.snowball.SnowballAnalyzer: [http] [www.yahoo.com] [foo] [bar.html] So this is the analyzer you want to use, right? Wildcards should work on "www.yahoo.*" What is the "German2" stemmer for Snowball? You've introduced a lot of variables to your equation here MultiFieldQueryParser and a non-standard Snowball stemmer. All of which I had to pull out of you for details, each of which is critical to understanding the problem. analyzer you are using, and also do the same on .toString of the query you parsed. Those two pieces of info will tell all. "url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo*" Well, I actually use a MultiFieldQueryParser, that's probably why the term does appear so often. Strange parser, it should be clear that am explicit "url:xyz" should only look in the url field, shouldn't it? Do you really need to query on multiple fields? Why not just use the plain QueryParser? If you need an aggregate field, create one at index time. QueryParsing is problematic enough, but adding in MFQP makes it even more complicated. Which Analyzer are you using for indexing? This same SnowballAnalyzer with "German2" stemmer? Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Saturday 03 April 2004 11:48, Erik Hatcher wrote: > Provide us the results of running your url through that, using the same SnowballAnalyzer("German2"): Analzying "http://www.yahoo.com/foo/bar.html"; org.apache.lucene.analysis.WhitespaceAnalyzer: [http://www.yahoo.com/foo/bar.html] org.apache.lucene.analysis.SimpleAnalyzer: [http] [www] [yahoo] [com] [foo] [bar] [html] org.apache.lucene.analysis.StopAnalyzer: [http] [www] [yahoo] [com] [foo] [bar] [html] org.apache.lucene.analysis.standard.StandardAnalyzer: [http] [www.yahoo.com] [foo] [bar.html] org.apache.lucene.analysis.snowball.SnowballAnalyzer: [http] [www.yahoo.com] [foo] [bar.html] > analyzer you are using, and also do the same on .toString of the query > you parsed. Those two pieces of info will tell all. "url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo* url:www.yahoo*" Well, I actually use a MultiFieldQueryParser, that's probably why the term does appear so often. Strange parser, it should be clear that am explicit "url:xyz" should only look in the url field, shouldn't it? Timo - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Apr 3, 2004, at 3:19 AM, [EMAIL PROTECTED] wrote: You *can* use wildcards with keywords (in fact, a keyword really has no meaning once indexed - everything is a "term" at that point). Well, I just tried. I also was surprised actually - but it just didn't work. I can use wildcards for doc.add(Field.Text("url", row.getString("url"))); but I cannot for doc.add(Field.Keyword("url", row.getString("url"))); - create a utility (I've posted one on the list in the past) that shows what your analyzer is doing graphically. Interesting. Can you give me subject/date of that posting? AnalysisDemo in this article: http://today.java.net/pub/a/today/2003/07/30/LuceneIntro.html Provide us the results of running your url through that, using the same analyzer you are using, and also do the same on .toString of the query you parsed. Those two pieces of info will tell all. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Friday 02 April 2004 23:48, Erik Hatcher wrote: > On Apr 2, 2004, at 10:00 AM, [EMAIL PROTECTED] wrote: > > On Saturday 13 March 2004 11:06, Otis Gospodnetic wrote: > >> Field.Keyword is suitable for storing data like Url. Give that a try. > > > > I just tried this a minute ago and found that I cannot use wildcards > > with > > Keywords: url:www.yahoo.* > > You *can* use wildcards with keywords (in fact, a keyword really has no > meaning once indexed - everything is a "term" at that point). Well, I just tried. I also was surprised actually - but it just didn't work. I can use wildcards for doc.add(Field.Text("url", row.getString("url"))); but I cannot for doc.add(Field.Keyword("url", row.getString("url"))); > - create a utility (I've posted one on the list in the past) that > shows what your analyzer is doing graphically. Interesting. Can you give me subject/date of that posting? Timo - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Apr 2, 2004, at 10:00 AM, [EMAIL PROTECTED] wrote: On Saturday 13 March 2004 11:06, Otis Gospodnetic wrote: Field.Keyword is suitable for storing data like Url. Give that a try. I just tried this a minute ago and found that I cannot use wildcards with Keywords: url:www.yahoo.* You *can* use wildcards with keywords (in fact, a keyword really has no meaning once indexed - everything is a "term" at that point). 99% of the issues people have with things like this end up being Analyzer/QueryParser related. A few quick pieces of advice: - use Luke to see what is inside your index and understand what it looks like from the inside. - create a utility (I've posted one on the list in the past) that shows what your analyzer is doing graphically. - use Query.toString to output what QueryParser did to your query expression. Armed with the above bits of trivia, you have the information to troubleshoot the situation first-hand. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Saturday 13 March 2004 11:06, Otis Gospodnetic wrote: > Field.Keyword is suitable for storing data like Url. Give that a try. I just tried this a minute ago and found that I cannot use wildcards with Keywords: url:www.yahoo.* - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Zero hits for queries ending with a number
Thanks Erik and Incze. Sorry for this lengthy post. Here is the class: import org.apache.lucene.analysis.*; import org.apache.lucene.analysis.standard.StandardFilter; import java.io.Reader; import java.util.Hashtable; public class KeywordAnalyzer extends Analyzer { public static final String[] STOP_WORDS = StopAnalyzer.ENGLISH_STOP_WORDS; private Hashtable stopTable; public KeywordAnalyzer() { this(STOP_WORDS); } public KeywordAnalyzer(String[] stopWords) { stopTable = StopFilter.makeStopTable(stopWords); } public TokenStream tokenStream(String fieldName, Reader reader) { TokenStream result = new NotTokenizingTokenizer(reader); result = new StandardFilter(result); result = new LowerCaseFilter(result); result = new StopFilter(result, stopTable); return result; } } I have retried everything with the new KeywordAnalyzer class, PerFieldAnalyzerWrapper, and with Field.Keyword. I don't get results for any searches, it doesn't even matter whether there is a number at the end or not. Using query.toString("url"): Query query = QueryParser.parse(terms, "contents", analyzer); logger.info("search method: query.toString for url= " + query.toString("url")); I can see what the analyzer is searching for. How do I determine what is the value stored in the index by Field.Keyword? I've tried: doc.add(Field.Keyword("url", url)); System.out.println("url: doc toString method= " + doc.toString()); But I don't know if this is the correct value that is compared with what the analyzer sends in. Thanks for the help. Morris -Original Message- From: Erik Hatcher [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 24, 2004 4:45 PM To: Lucene Users List Subject: Re: Zero hits for queries ending with a number On Mar 24, 2004, at 5:58 PM, Morris Mizrahi wrote: > I think the custom analyzer I created is not properly doing what a > KeywordAnalyzer would do. > > Erik, could you please post what KeywordAnalyzer should look like? It should simply "tokenize" the entire input as a single token. Incze Lajos posted a NonTokenizingTokenizer early today, in fact, that does the trick. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Mar 24, 2004, at 5:58 PM, Morris Mizrahi wrote: I think the custom analyzer I created is not properly doing what a KeywordAnalyzer would do. Erik, could you please post what KeywordAnalyzer should look like? It should simply "tokenize" the entire input as a single token. Incze Lajos posted a NonTokenizingTokenizer early today, in fact, that does the trick. Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Zero hits for queries ending with a number
Thanks to Otis, Morus, and Erik for their responses to my question. I see that my question is also related to the posting: "Query syntax on Keyword field question". I tried all of your suggestions. When using: a) the tokens generated by the analyzer and b) the parsed query (using the to_string method). to debug StandardAnalyzer, I saw that it does properly pass in the string with the number attached to it. I don't understand why Field.Text did not work with StandardAnalyzer. I tried WhitespaceAnalyzer and that did not work. I have tried implementing a custom analyzer like KeywordAnalyzer, and using PerFieldAnalyzerWrapper. I think the custom analyzer I created is not properly doing what a KeywordAnalyzer would do. Erik, could you please post what KeywordAnalyzer should look like? I can't wait until the book you guys are developing comes out. Thanks very much. Morris -Original Message- From: Erik Hatcher [mailto:[EMAIL PROTECTED] Sent: Saturday, March 13, 2004 3:14 AM To: Lucene Users List Subject: Re: Zero hits for queries ending with a number On Mar 13, 2004, at 6:02 AM, Morus Walter wrote: > Otis Gospodnetic writes: >> Field.Keyword is suitable for storing data like Url. Give that a try. >> > Hmm. I don't think keyword fields can be used with query parser, > which is probably one of the problems here. > He did try keyword fields. Look in the archives for KeywordAnalyzer (custom) and PerFieldAnalyzerWrapper (built-in) using a combination of these you can use keyword fields. Or, first try just using WhitespaceAnalyzer. It is almost always the analyzer that is the cause of confusion - folks just get lulled into forgetting about its role because Lucene is so easy to use... until this type of issue bites you. It is a wacky combination though - and notorious for causing confusion. Perhaps someone could create a wiki page for this scenario where we can flesh out examples/solutions? Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
On Mar 13, 2004, at 6:02 AM, Morus Walter wrote: Otis Gospodnetic writes: Field.Keyword is suitable for storing data like Url. Give that a try. Hmm. I don't think keyword fields can be used with query parser, which is probably one of the problems here. He did try keyword fields. Look in the archives for KeywordAnalyzer (custom) and PerFieldAnalyzerWrapper (built-in) using a combination of these you can use keyword fields. Or, first try just using WhitespaceAnalyzer. It is almost always the analyzer that is the cause of confusion - folks just get lulled into forgetting about its role because Lucene is so easy to use... until this type of issue bites you. It is a wacky combination though - and notorious for causing confusion. Perhaps someone could create a wiki page for this scenario where we can flesh out examples/solutions? Erik - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
Otis Gospodnetic writes: > Field.Keyword is suitable for storing data like Url. Give that a try. > Hmm. I don't think keyword fields can be used with query parser, which is probably one of the problems here. He did try keyword fields. IMO it should work with a text field and the same analyzer for indexing and query parser though it might return additional hits. The latter issue is why it's usually a bad idea not to use keyword for url values, I agree with that. It should be possible to see what's going wrong from looking at a) the tokens generated by the analyzer and b) the parsed query (using the to_string method). But I'm just curious to understand why it's not working. At the end, I'd also suggest a keyword field and not using query parser for this field. Creating queries without query parser isn't hard. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Zero hits for queries ending with a number
Field.Keyword is suitable for storing data like Url. Give that a try. Otis --- Morris Mizrahi <[EMAIL PROTECTED]> wrote: > Hey everyone. > > > > My document object for my lucene index has a "url" field. > > I have created "url" as a Text field. > > The problem I am having is that searches with a "url" that end with a > number, e.g. "e:\k2_beta1", don't return any hits even though there > is > data that should match this search criteria. If you have a "url" that > ends with a letter, e.g. "e:\k2_alpha", the search works fine and > returns the correct hits. > > > > Here are some code snippets of my work: > > IndexCreation: > > writer = new IndexWriter("index", new StandardAnalyzer(), true); > > > > create the "url" as a Text field: > > doc.add(Field.Text("url", url)); > > > > search code: > > Analyzer analyzer = new StandardAnalyzer(); > > DateFilter filter = ((SearchForm) form).getDateFilter(); > > Searcher searcher = new > IndexSearcher(IndexReader.open(indexPath)); > > Query query = QueryParser.parse(terms, "contents", analyzer); > > Hits hits = searcher.search(query, filter); > > > > I have tried changing the "url" field from Text to Keyword. > > This didn't work and also caused my searches for any "url" to fail. > > I am using lucene 1.2 > > > > I know I need the proper combinations of Analyzer and Field type. > > > > Any help would be appreciated. > > > > Thanks. > > > > Morris > > > > - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Zero hits for queries ending with a number
Hey everyone. My document object for my lucene index has a "url" field. I have created "url" as a Text field. The problem I am having is that searches with a "url" that end with a number, e.g. "e:\k2_beta1", don't return any hits even though there is data that should match this search criteria. If you have a "url" that ends with a letter, e.g. "e:\k2_alpha", the search works fine and returns the correct hits. Here are some code snippets of my work: IndexCreation: writer = new IndexWriter("index", new StandardAnalyzer(), true); create the "url" as a Text field: doc.add(Field.Text("url", url)); search code: Analyzer analyzer = new StandardAnalyzer(); DateFilter filter = ((SearchForm) form).getDateFilter(); Searcher searcher = new IndexSearcher(IndexReader.open(indexPath)); Query query = QueryParser.parse(terms, "contents", analyzer); Hits hits = searcher.search(query, filter); I have tried changing the "url" field from Text to Keyword. This didn't work and also caused my searches for any "url" to fail. I am using lucene 1.2 I know I need the proper combinations of Analyzer and Field type. Any help would be appreciated. Thanks. Morris