lucene/CHANGES.txt

Lucene Change Log

$Id$

2.0 RC1

API Changes

 1. All deprecated methods and fields have been removed, except
    DateField, which will still be supported for some time
    so Lucene can read its date fields from old indexes
    (Yonik Seeley & Grant Ingersoll)

 2. DisjunctionSumScorer is no longer public.
    (Paul Elschot via Otis Gospodnetic)
    
 3. Creating a Field with both an empty name and an empty value 
    now throws an IllegalArgumentException
    (Daniel Naber)

Bug fixes

 1. LUCENE-330: Fix issue of FilteredQuery not working properly within
    BooleanQuery.  (Paul Elschot via Erik Hatcher)

 2. LUCENE-515: Make ConstantScoreRangeQuery and ConstantScoreQuery work
    with RemoteSearchable.  (Philippe Laflamme via Yonik Seeley)

 3. Added methods to get/set writeLockTimeout and commitLockTimeout in
    IndexWriter. These could be set in Lucene 1.4 using a system property.
    This feature had been removed without adding the corresponding
    getter/setter methods.  (Daniel Naber)

 4. LUCENE-413: Fixed ArrayIndexOutOfBoundsException exceptions
    when using SpanQueries. (Paul Elschot via Yonik Seeley)

 5. Implemented FilterIndexReader.getVersion() and isCurrent()
    (Yonik Seeley)

 6. LUCENE-540: Fixed a bug with IndexWriter.addIndexes(Directory[])
    that sometimes caused the index order of documents to change.
    (Yonik Seeley)

 7. LUCENE-526: Fixed a bug in FieldSortedHitQueue that caused
    subsequent String sorts with different locales to sort identically.
    (Paul Cowan via Yonik Seeley)

 8. LUCENE-541: Add missing extractTerms() to DisjunctionMaxQuery
    (Stefan Will via Yonik Seeley)

 9. LUCENE-514: Added getTermArrays() and extractTerms() to
    MultiPhraseQuery (Eric Jain & Yonik Seeley)

10. LUCENE-512: Fixed ClassCastException in ParallelReader.getTermFreqVectors
    (frederic via Yonik)

1.9.1

Bug fixes

 1. LUCENE-511: Fix a bug in the BufferedIndexOutput optimization
    introduced in 1.9-final.  (Shay Banon & Steven Tamm via cutting)

1.9 final

Note that this realease is mostly but not 100% source compatible with
the previous release of Lucene (1.4.3). In other words, you should
make sure your application compiles with this version of Lucene before
you replace the old Lucene JAR with the new one.  Many methods have
been deprecated in anticipation of release 2.0, so deprecation
warnings are to be expected when upgrading from 1.4.3 to 1.9.

Bug fixes
 
 1. The fix that made IndexWriter.setMaxBufferedDocs(1) work had negative 
    effects on indexing performance and has thus been reverted. The 
    argument for setMaxBufferedDocs(int) must now at least be 2, otherwise
    an exception is thrown. (Daniel Naber)
 
Optimizations
     
 1. Optimized BufferedIndexOutput.writeBytes() to use
    System.arraycopy() in more cases, rather than copying byte-by-byte.
    (Lukas Zapletal via Cutting)

1.9 RC1

Requirements

 1. To compile and use Lucene you now need Java 1.4 or later.

Changes in runtime behavior

 1. FuzzyQuery can no longer throw a TooManyClauses exception. If a
    FuzzyQuery expands to more than BooleanQuery.maxClauseCount
    terms only the BooleanQuery.maxClauseCount most similar terms
    go into the rewritten query and thus the exception is avoided.
    (Christoph)

 2. Changed system property from "org.apache.lucene.lockdir" to
    "org.apache.lucene.lockDir", so that its casing follows the existing
    pattern used in other Lucene system properties. (Bernhard)

 3. The terms of RangeQueries and FuzzyQueries are now converted to
    lowercase by default (as it has been the case for PrefixQueries
    and WildcardQueries before). Use setLowercaseExpandedTerms(false)
    to disable that behavior but note that this also affects
    PrefixQueries and WildcardQueries. (Daniel Naber)

 4. Document frequency that is computed when MultiSearcher is used is now
    computed correctly and "globally" across subsearchers and indices, while
    before it used to be computed locally to each index, which caused
    ranking across multiple indices not to be equivalent.
    (Chuck Williams, Wolf Siberski via Otis, bug #31841)

 5. When opening an IndexWriter with create=true, Lucene now only deletes
    its own files from the index directory (looking at the file name suffixes
    to decide if a file belongs to Lucene). The old behavior was to delete
    all files. (Daniel Naber and Bernhard Messer, bug #34695)

 6. The version of an IndexReader, as returned by getCurrentVersion()
    and getVersion() doesn't start at 0 anymore for new indexes. Instead, it
    is now initialized by the system time in milliseconds.
    (Bernhard Messer via Daniel Naber)

 7. Several default values cannot be set via system properties anymore, as
    this has been considered inappropriate for a library like Lucene. For
    most properties there are set/get methods available in IndexWriter which
    you should use instead. This affects the following properties:
    See IndexWriter for getter/setter methods:
      org.apache.lucene.writeLockTimeout, org.apache.lucene.commitLockTimeout,
      org.apache.lucene.minMergeDocs, org.apache.lucene.maxMergeDocs,
      org.apache.lucene.maxFieldLength, org.apache.lucene.termIndexInterval,
      org.apache.lucene.mergeFactor,
    See BooleanQuery for getter/setter methods:
      org.apache.lucene.maxClauseCount
    See FSDirectory for getter/setter methods:
      disableLuceneLocks
    (Daniel Naber)

 8. Fixed FieldCacheImpl to use user-provided IntParser and FloatParser,
    instead of using Integer and Float classes for parsing.
    (Yonik Seeley via Otis Gospodnetic)

 9. Expert level search routines returning TopDocs and TopFieldDocs
    no longer normalize scores.  This also fixes bugs related to
    MultiSearchers and score sorting/normalization.
    (Luc Vanlerberghe via Yonik Seeley, LUCENE-469)

New features

 1. Added support for stored compressed fields (patch #31149)
    (Bernhard Messer via Christoph)

 2. Added support for binary stored fields (patch #29370)
    (Drew Farris and Bernhard Messer via Christoph)

 3. Added support for position and offset information in term vectors
    (patch #18927). (Grant Ingersoll & Christoph)

 4. A new class DateTools has been added. It allows you to format dates
    in a readable format adequate for indexing. Unlike the existing
    DateField class DateTools can cope with dates before 1970 and it
    forces you to specify the desired date resolution (e.g. month, day,
    second, ...) which can make RangeQuerys on those fields more efficient.
    (Daniel Naber)

 5. QueryParser now correctly works with Analyzers that can return more
    than one token per position. For example, a query "+fast +car"
    would be parsed as "+fast +(car automobile)" if the Analyzer
    returns "car" and "automobile" at the same position whenever it
    finds "car" (Patch #23307).
    (Pierrick Brihaye, Daniel Naber)

 6. Permit unbuffered Directory implementations (e.g., using mmap).
    InputStream is replaced by the new classes IndexInput and
    BufferedIndexInput.  OutputStream is replaced by the new classes
    IndexOutput and BufferedIndexOutput.  InputStream and OutputStream
    are now deprecated and FSDirectory is now subclassable. (cutting)

 7. Add native Directory and TermDocs implementations that work under
    GCJ.  These require GCC 3.4.0 or later and have only been tested
    on Linux.  Use 'ant gcj' to build demo applications. (cutting)

 8. Add MMapDirectory, which uses nio to mmap input files.  This is
    still somewhat slower than FSDirectory.  However it uses less
    memory per query term, since a new buffer is not allocated per
    term, which may help applications which use, e.g., wildcard
    queries.  It may also someday be faster. (cutting & Paul Elschot)

 9. Added javadocs-internal to build.xml - bug #30360
    (Paul Elschot via Otis)

10. Added RangeFilter, a more generically useful filter than DateFilter.
    (Chris M Hostetter via Erik)

11. Added NumberTools, a utility class indexing numeric fields.
    (adapted from code contributed by Matt Quail; committed by Erik)

12. Added public static IndexReader.main(String[] args) method.
    IndexReader can now be used directly at command line level
    to list and optionally extract the individual files from an existing
    compound index file.
    (adapted from code contributed by Garrett Rooney; committed by Bernhard)

13. Add IndexWriter.setTermIndexInterval() method.  See javadocs.
    (Doug Cutting)

14. Added LucenePackage, whose static get() method returns java.util.Package,
    which lets the caller get the Lucene version information specified in
    the Lucene Jar.
    (Doug Cutting via Otis)

15. Added Hits.iterator() method and corresponding HitIterator and Hit objects.
    This provides standard java.util.Iterator iteration over Hits.
    Each call to the iterator's next() method returns a Hit object.
    (Jeremy Rayner via Erik)

16. Add ParallelReader, an IndexReader that combines separate indexes
    over different fields into a single virtual index.  (Doug Cutting)

17. Add IntParser and FloatParser interfaces to FieldCache, so that
    fields in arbitrarily formats can be cached as ints and floats.
    (Doug Cutting)

18. Added class org.apache.lucene.index.IndexModifier which combines
    IndexWriter and IndexReader, so you can add and delete documents without
    worrying about synchronisation/locking issues.
    (Daniel Naber)

19. Lucene can now be used inside an unsigned applet, as Lucene's access
    to system properties will not cause a SecurityException anymore.
    (Jon Schuster via Daniel Naber, bug #34359)

20. Added a new class MatchAllDocsQuery that matches all documents.
    (John Wang via Daniel Naber, bug #34946)

21. Added ability to omit norms on a per field basis to decrease
    index size and memory consumption when there are many indexed fields.
    See Field.setOmitNorms()
    (Yonik Seeley, LUCENE-448)

22. Added NullFragmenter to contrib/highlighter, which is useful for
    highlighting entire documents or fields.
    (Erik Hatcher)

23. Added regular expression queries, RegexQuery and SpanRegexQuery.
    Note the same term enumeration caveats apply with these queries as
    apply to WildcardQuery and other term expanding queries.
    These two new queries are not currently supported via QueryParser.
    (Erik Hatcher)

24. Added ConstantScoreQuery which wraps a filter and produces a score
    equal to the query boost for every matching document.
    (Yonik Seeley, LUCENE-383)

25. Added ConstantScoreRangeQuery which produces a constant score for
    every document in the range.  One advantage over a normal RangeQuery
    is that it doesn't expand to a BooleanQuery and thus doesn't have a maximum
    number of terms the range can cover.  Both endpoints may also be open.
    (Yonik Seeley, LUCENE-383)

26. Added ability to specify a minimum number of optional clauses that
    must match in a BooleanQuery.  See BooleanQuery.setMinimumNumberShouldMatch().
    (Paul Elschot, Chris Hostetter via Yonik Seeley, LUCENE-395)

27. Added DisjunctionMaxQuery which provides the maximum score across it's clauses.
    It's very useful for searching across multiple fields.
    (Chuck Williams via Yonik Seeley, LUCENE-323)

28. New class ISOLatin1AccentFilter that replaces accented characters in the ISO
    Latin 1 character set by their unaccented equivalent.
    (Sven Duzont via Erik Hatcher)

29. New class KeywordAnalyzer. "Tokenizes" the entire stream as a single token.
    This is useful for data like zip codes, ids, and some product names.
    (Erik Hatcher)

30. Copied LengthFilter from contrib area to core. Removes words that are too
    long and too short from the stream.
    (David Spencer via Otis and Daniel)

31. Added getPositionIncrementGap(String fieldName) to Analyzer.  This allows
    custom analyzers to put gaps between Field instances with the same field
    name, preventing phrase or span queries crossing these boundaries.  The
    default implementation issues a gap of 0, allowing the default token
    position increment of 1 to put the next field's first token into a
    successive position.
    (Erik Hatcher, with advice from Yonik)

32. StopFilter can now ignore case when checking for stop words.
    (Grant Ingersoll via Yonik, LUCENE-248)

33. Add TopDocCollector and TopFieldDocCollector.  These simplify the
    implementation of hit collectors that collect only the
    top-scoring or top-sorting hits.

API Changes

 1. Several methods and fields have been deprecated. The API documentation
    contains information about the recommended replacements. It is planned
    that most of the deprecated methods and fields will be removed in
    Lucene 2.0. (Daniel Naber)

 2. The Russian and the German analyzers have been moved to contrib/analyzers.
    Also, the WordlistLoader class has been moved one level up in the
    hierarchy and is now org.apache.lucene.analysis.WordlistLoader
    (Daniel Naber)

 3. The API contained methods that declared to throw an IOException
    but that never did this. These declarations have been removed. If
    your code tries to catch these exceptions you might need to remove
    those catch clauses to avoid compile errors. (Daniel Naber)

 4. Add a serializable Parameter Class to standardize parameter enum
    classes in BooleanClause and Field. (Christoph)

 5. Added rewrite methods to all SpanQuery subclasses that nest other SpanQuerys.
    This allows custom SpanQuery subclasses that rewrite (for term expansion, for
    example) to nest within the built-in SpanQuery classes successfully.

Bug fixes

 1. The JSP demo page (src/jsp/results.jsp) now properly closes the
    IndexSearcher it opens. (Daniel Naber)

 2. Fixed a bug in IndexWriter.addIndexes(IndexReader[] readers) that
    prevented deletion of obsolete segments. (Christoph Goller)

 3. Fix in FieldInfos to avoid the return of an extra blank field in
    IndexReader.getFieldNames() (Patch #19058). (Mark Harwood via Bernhard)

 4. Some combinations of BooleanQuery and MultiPhraseQuery (formerly
    PhrasePrefixQuery) could provoke UnsupportedOperationException
    (bug #33161). (Rhett Sutphin via Daniel Naber)

 5. Small bug in skipTo of ConjunctionScorer that caused NullPointerException
    if skipTo() was called without prior call to next() fixed. (Christoph)

 6. Disable Similiarty.coord() in the scoring of most automatically
    generated boolean queries.  The coord() score factor is
    appropriate when clauses are independently specified by a user,
    but is usually not appropriate when clauses are generated
    automatically, e.g., by a fuzzy, wildcard or range query.  Matches
    on such automatically generated queries are no longer penalized
    for not matching all terms.  (Doug Cutting, Patch #33472)

 7. Getting a lock file with Lock.obtain(long) was supposed to wait for
    a given amount of milliseconds, but this didn't work.
    (John Wang via Daniel Naber, Bug #33799)

 8. Fix FSDirectory.createOutput() to always create new files.
    Previously, existing files were overwritten, and an index could be
    corrupted when the old version of a file was longer than the new.
    Now any existing file is first removed.  (Doug Cutting)

 9. Fix BooleanQuery containing nested SpanTermQuery's, which previously
    could return an incorrect number of hits.
    (Reece Wilton via Erik Hatcher, Bug #35157)

10. Fix NullPointerException that could occur with a MultiPhraseQuery
    inside a BooleanQuery.
    (Hans Hjelm and Scotty Allen via Daniel Naber, Bug #35626)

11. Fixed SnowballFilter to pass through the position increment from
    the original token.
    (Yonik Seeley via Erik Hatcher, LUCENE-437)

12. Added Unicode range of Korean characters to StandardTokenizer,
    grouping contiguous characters into a token rather than one token
    per character.  This change also changes the token type to "<CJ>"
    for Chinese and Japanese character tokens (previously it was "<CJK>").
    (Cheolgoo Kang via Otis and Erik, LUCENE-444 and LUCENE-461)

13. FieldsReader now looks at FieldInfo.storeOffsetWithTermVector and
    FieldInfo.storePositionWithTermVector and creates the Field with
    correct TermVector parameter.
    (Frank Steinmann via Bernhard, LUCENE-455)

14. Fixed WildcardQuery to prevent "cat" matching "ca??".
    (Xiaozheng Ma via Bernhard, LUCENE-306)

15. Fixed a bug where MultiSearcher and ParallelMultiSearcher could
    change the sort order when sorting by string for documents without
    a value for the sort field.
    (Luc Vanlerberghe via Yonik, LUCENE-453)

16. Fixed a sorting problem with MultiSearchers that can lead to
    missing or duplicate docs due to equal docs sorting in an arbitrary order.
    (Yonik Seeley, LUCENE-456)

17. A single hit using the expert level sorted search methods
    resulted in the score not being normalized.
    (Yonik Seeley, LUCENE-462)

18. Fixed inefficient memory usage when loading an index into RAMDirectory.
    (Volodymyr Bychkoviak via Bernhard, LUCENE-475)

19. Corrected term offsets returned by ChineseTokenizer.
    (Ray Tsang via Erik Hatcher, LUCENE-324)

20. Fixed MultiReader.undeleteAll() to correctly update numDocs.
    (Robert Kirchgessner via Doug Cutting, LUCENE-479)

21. Race condition in IndexReader.getCurrentVersion() and isCurrent()
    fixed by aquiring the commit lock.
    (Luc Vanlerberghe via Yonik Seeley, LUCENE-481)

22. IndexWriter.setMaxBufferedDocs(1) didn't have the expected effect,
    this has now been fixed. (Daniel Naber)

23. Fixed QueryParser when called with a date in local form like 
    "[1/16/2000 TO 1/18/2000]". This query did not include the documents
    of 1/18/2000, i.e. the last day was not included. (Daniel Naber)

24. Removed sorting constraint that threw an exception if there were
    not yet any values for the sort field (Yonik Seeley, LUCENE-374)

Optimizations
     
 1. Disk usage (peak requirements during indexing and optimization)
    in case of compound file format has been improved. 
    (Bernhard, Dmitry, and Christoph)

 2. Optimize the performance of certain uses of BooleanScorer,
    TermScorer and IndexSearcher.  In particular, a BooleanQuery
    composed of TermQuery, with not all terms required, that returns a
    TopDocs (e.g., through a Hits with no Sort specified) runs much
    faster.  (cutting)
    
 3. Removed synchronization from reading of term vectors with an
    IndexReader (Patch #30736). (Bernhard Messer via Christoph)

 4. Optimize term-dictionary lookup to allocate far fewer terms when
    scanning for the matching term.  This speeds searches involving
    low-frequency terms, where the cost of dictionary lookup can be
    significant. (cutting)

 5. Optimize fuzzy queries so the standard fuzzy queries with a prefix 
    of 0 now run 20-50% faster (Patch #31882).
    (Jonathan Hager via Daniel Naber)
    
 6. A Version of BooleanScorer (BooleanScorer2) added that delivers
    documents in increasing order and implements skipTo. For queries
    with required or forbidden clauses it may be faster than the old
    BooleanScorer, for BooleanQueries consisting only of optional
    clauses it is probably slower. The new BooleanScorer is now the
    default. (Patch 31785 by Paul Elschot via Christoph)

 7. Use uncached access to norms when merging to reduce RAM usage.
    (Bug #32847).  (Doug Cutting)

 8. Don't read term index when random-access is not required.  This
    reduces time to open IndexReaders and they use less memory when
    random access is not required, e.g., when merging segments.  The
    term index is now read into memory lazily at the first
    random-access.  (Doug Cutting)

 9. Optimize IndexWriter.addIndexes(Directory[]) when the number of
    added indexes is larger than mergeFactor.  Previously this could
    result in quadratic performance.  Now performance is n log(n).
    (Doug Cutting)

10. Speed up the creation of TermEnum for indicies with multiple
    segments and deleted documents, and thus speed up PrefixQuery,
    RangeQuery, WildcardQuery, FuzzyQuery, RangeFilter, DateFilter,
    and sorting the first time on a field.
    (Yonik Seeley, LUCENE-454)

11. Optimized and generalized 32 bit floating point to byte
    (custom 8 bit floating point) conversions.  Increased the speed of
    Similarity.encodeNorm() anywhere from 10% to 250%, depending on the JVM.
    (Yonik Seeley, LUCENE-467)

Infrastructure

 1. Lucene's source code repository has converted from CVS to
    Subversion.  The new repository is at
    http://svn.apache.org/repos/asf/lucene/java/trunk

 2. Lucene's issue tracker has migrated from Bugzilla to JIRA.
    Lucene's JIRA is at http://issues.apache.org/jira/browse/LUCENE
    The old issues are still available at
    http://issues.apache.org/bugzilla/show_bug.cgi?id=xxxx
    (use the bug number instead of xxxx)


1.4.3

 1. The JSP demo page (src/jsp/results.jsp) now properly escapes error
    messages which might contain user input (e.g. error messages about 
    query parsing). If you used that page as a starting point for your
    own code please make sure your code also properly escapes HTML
    characters from user input in order to avoid so-called cross site
    scripting attacks. (Daniel Naber)
  
  2. QueryParser changes in 1.4.2 broke the QueryParser API. Now the old 
     API is supported again. (Christoph)


1.4.2

 1. Fixed bug #31241: Sorting could lead to incorrect results (documents
    missing, others duplicated) if the sort keys were not unique and there
    were more than 100 matches. (Daniel Naber)

 2. Memory leak in Sort code (bug #31240) eliminated.
    (Rafal Krzewski via Christoph and Daniel)
    
 3. FuzzyQuery now takes an additional parameter that specifies the
    minimum similarity that is required for a term to match the query.
    The QueryParser syntax for this is term~x, where x is a floating 
    point number >= 0 and < 1 (a bigger number means that a higher
    similarity is required). Furthermore, a prefix can be specified
    for FuzzyQuerys so that only those terms are considered similar that 
    start with this prefix. This can speed up FuzzyQuery greatly.
    (Daniel Naber, Christoph Goller)
    
 4. PhraseQuery and PhrasePrefixQuery now allow the explicit specification
    of relative positions. (Christoph Goller)
    
 5. QueryParser changes: Fix for ArrayIndexOutOfBoundsExceptions 
    (patch #9110); some unused method parameters removed; The ability
    to specify a minimum similarity for FuzzyQuery has been added.
    (Christoph Goller)

 6. IndexSearcher optimization: a new ScoreDoc is no longer allocated
    for every non-zero-scoring hit.  This makes 'OR' queries that
    contain common terms substantially faster.  (cutting)


1.4.1

 1. Fixed a performance bug in hit sorting code, where values were not
    correctly cached.  (Aviran via cutting)

 2. Fixed errors in file format documentation. (Daniel Naber)


1.4 final

 1. Added "an" to the list of stop words in StopAnalyzer, to complement
    the existing "a" there.  Fix for bug 28960
     (http://issues.apache.org/bugzilla/show_bug.cgi?id=28960). (Otis)

 2. Added new class FieldCache to manage in-memory caches of field term
    values.  (Tim Jones)

 3. Added overloaded getFieldQuery method to QueryParser which
    accepts the slop factor specified for the phrase (or the default
    phrase slop for the QueryParser instance).  This allows overriding
    methods to replace a PhraseQuery with a SpanNearQuery instead,
    keeping the proper slop factor. (Erik Hatcher)

 4. Changed the encoding of GermanAnalyzer.java and GermanStemmer.java to
    UTF-8 and changed the build encoding to UTF-8, to make changed files
    compile. (Otis Gospodnetic)

 5. Removed synchronization from term lookup under IndexReader methods
    termFreq(), termDocs() or termPositions() to improve
    multi-threaded performance.  (cutting)

 6. Fix a bug where obsolete segment files were not deleted on Win32.


1.4 RC3

 1. Fixed several search bugs introduced by the skipTo() changes in
    release 1.4RC1.  The index file format was changed a bit, so
    collections must be re-indexed to take advantage of the skipTo()
    optimizations.  (Christoph Goller)

 2. Added new Document methods, removeField() and removeFields().
    (Christoph Goller)

 3. Fixed inconsistencies with index closing.  Indexes and directories
    are now only closed automatically by Lucene when Lucene opened
    them automatically.  (Christoph Goller)

 4. Added new class: FilteredQuery.  (Tim Jones)

 5. Added a new SortField type for custom comparators.  (Tim Jones)

 6. Lock obtain timed out message now displays the full path to the lock
    file. (Daniel Naber via Erik)

 7. Fixed a bug in SpanNearQuery when ordered. (Paul Elschot via cutting)

 8. Fixed so that FSDirectory's locks still work when the
    java.io.tmpdir system property is null.  (cutting)

 9. Changed FilteredTermEnum's constructor to take no parameters,
    as the parameters were ignored anyway (bug #28858)

1.4 RC2

 1. GermanAnalyzer now throws an exception if the stopword file
    cannot be found (bug #27987). It now uses LowerCaseFilter
    (bug #18410) (Daniel Naber via Otis, Erik)

 2. Fixed a few bugs in the file format documentation. (cutting)


1.4 RC1

 1. Changed the format of the .tis file, so that:

    - it has a format version number, which makes it easier to
      back-compatibly change file formats in the future.

    - the term count is now stored as a long.  This was the one aspect
      of the Lucene's file formats which limited index size.

    - a few internal index parameters are now stored in the index, so
      that they can (in theory) now be changed from index to index,
      although there is not yet an API to do so.

    These changes are back compatible.  The new code can read old
    indexes.  But old code will not be able read new indexes. (cutting)

 2. Added an optimized implementation of TermDocs.skipTo().  A skip
    table is now stored for each term in the .frq file.  This only
    adds a percent or two to overall index size, but can substantially
    speedup many searches.  (cutting)

 3. Restructured the Scorer API and all Scorer implementations to take
    advantage of an optimized TermDocs.skipTo() implementation.  In
    particular, PhraseQuerys and conjunctive BooleanQuerys are
    faster when one clause has substantially fewer matches than the
    others.  (A conjunctive BooleanQuery is a BooleanQuery where all
    clauses are required.)  (cutting)

 4. Added new class ParallelMultiSearcher.  Combined with
    RemoteSearchable this makes it easy to implement distributed
    search systems.  (Jean-Francois Halleux via cutting)

 5. Added support for hit sorting.  Results may now be sorted by any
    indexed field.  For details see the javadoc for
    Searcher#search(Query, Sort).  (Tim Jones via Cutting)

 6. Changed FSDirectory to auto-create a full directory tree that it
    needs by using mkdirs() instead of mkdir().  (Mladen Turk via Otis)

 7. Added a new span-based query API.  This implements, among other
    things, nested phrases.  See javadocs for details.  (Doug Cutting)

 8. Added new method Query.getSimilarity(Searcher), and changed
    scorers to use it.  This permits one to subclass a Query class so
    that it can specify it's own Similarity implementation, perhaps
    one that delegates through that of the Searcher.  (Julien Nioche
    via Cutting)

 9. Added MultiReader, an IndexReader that combines multiple other
    IndexReaders.  (Cutting)

10. Added support for term vectors.  See Field#isTermVectorStored().
    (Grant Ingersoll, Cutting & Dmitry)

11. Fixed the old bug with escaping of special characters in query
    strings: http://issues.apache.org/bugzilla/show_bug.cgi?id=24665
    (Jean-Francois Halleux via Otis)

12. Added support for overriding default values for the following,
    using system properties:
      - default commit lock timeout
      - default maxFieldLength
      - default maxMergeDocs
      - default mergeFactor
      - default minMergeDocs
      - default write lock timeout
    (Otis)

13. Changed QueryParser.jj to allow '-' and '+' within tokens:
    http://issues.apache.org/bugzilla/show_bug.cgi?id=27491
    (Morus Walter via Otis)

14. Changed so that the compound index format is used by default.
    This makes indexing a bit slower, but vastly reduces the chances
    of file handle problems.  (Cutting)


1.3 final

 1. Added catch of BooleanQuery$TooManyClauses in QueryParser to
    throw ParseException instead. (Erik Hatcher)

 2. Fixed a NullPointerException in Query.explain(). (Doug Cutting)

 3. Added a new method IndexReader.setNorm(), that permits one to
    alter the boosting of fields after an index is created.

 4. Distinguish between the final position and length when indexing a
    field.  The length is now defined as the total number of tokens,
    instead of the final position, as it was previously.  Length is
    used for score normalization (Similarity.lengthNorm()) and for
    controlling memory usage (IndexWriter.maxFieldLength).  In both of
    these cases, the total number of tokens is a better value to use
    than the final token position.  Position is used in phrase
    searching (see PhraseQuery and Token.setPositionIncrement()).

 5. Fix StandardTokenizer's handling of CJK characters (Chinese,
    Japanese and Korean ideograms).  Previously contiguous sequences
    were combined in a single token, which is not very useful.  Now
    each ideogram generates a separate token, which is more useful.


1.3 RC3

 1. Added minMergeDocs in IndexWriter.  This can be raised to speed
    indexing without altering the number of files, but only using more
    memory.  (Julien Nioche via Otis)

 2. Fix bug #24786, in query rewriting. (bschneeman via Cutting)

 3. Fix bug #16952, in demo HTML parser, skip comments in
    javascript. (Christoph Goller)

 4. Fix bug #19253, in demo HTML parser, add whitespace as needed to
    output (Daniel Naber via Christoph Goller)

 5. Fix bug #24301, in demo HTML parser, long titles no longer
    hang things. (Christoph Goller)

 6. Fix bug #23534, Replace use of file timestamp of segments file
    with an index version number stored in the segments file.  This
    resolves problems when running on file systems with low-resolution
    timestamps, e.g., HFS under MacOS X.  (Christoph Goller)

 7. Fix QueryParser so that TokenMgrError is not thrown, only
    ParseException.  (Erik Hatcher)

 8. Fix some bugs introduced by change 11 of RC2.  (Christoph Goller)

 9. Fixed a problem compiling TestRussianStem.  (Christoph Goller)

10. Cleaned up some build stuff.  (Erik Hatcher)


1.3 RC2

 1. Added getFieldNames(boolean) to IndexReader, SegmentReader, and
    SegmentsReader. (Julien Nioche via otis)

 2. Changed file locking to place lock files in
    System.getProperty("java.io.tmpdir"), where all users are
    permitted to write files.  This way folks can open and correctly
    lock indexes which are read-only to them.

 3. IndexWriter: added a new method, addDocument(Document, Analyzer),
    permitting one to easily use different analyzers for different
    documents in the same index.

 4. Minor enhancements to FuzzyTermEnum.
    (Christoph Goller via Otis)

 5. PriorityQueue: added insert(Object) method and adjusted IndexSearcher
    and MultiIndexSearcher to use it.
    (Christoph Goller via Otis)

 6. Fixed a bug in IndexWriter that returned incorrect docCount().
    (Christoph Goller via Otis)

 7. Fixed SegmentsReader to eliminate the confusing and slightly different
    behaviour of TermEnum when dealing with an enumeration of all terms,
    versus an enumeration starting from a specific term.
    This patch also fixes incorrect term document frequences when the same term
    is present in multiple segments.
    (Christoph Goller via Otis)

 8. Added CachingWrapperFilter and PerFieldAnalyzerWrapper. (Erik Hatcher)

 9. Added support for the new "compound file" index format (Dmitry
    Serebrennikov)

10. Added Locale setting to QueryParser, for use by date range parsing.

11. Changed IndexReader so that it can be subclassed by classes
    outside of its package.  Previously it had package-private
    abstract methods.  Also modified the index merging code so that it
    can work on an arbitrary IndexReader implementation, and added a
    new method, IndexWriter.addIndexes(IndexReader[]), to take
    advantage of this. (cutting)

12. Added a limit to the number of clauses which may be added to a
    BooleanQuery.  The default limit is 1024 clauses.  This should
    stop most OutOfMemoryExceptions by prefix, wildcard and fuzzy
    queries which run amok. (cutting)

13. Add new method: IndexReader.undeleteAll().  This undeletes all
    deleted documents which still remain in the index. (cutting)


1.3 RC1

 1. Fixed PriorityQueue's clear() method.
    Fix for bug 9454, http://nagoya.apache.org/bugzilla/show_bug.cgi?id=9454
    (Matthijs Bomhoff via otis)

 2. Changed StandardTokenizer.jj grammar for EMAIL tokens.
    Fix for bug 9015, http://nagoya.apache.org/bugzilla/show_bug.cgi?id=9015
    (Dale Anson via otis)

 3. Added the ability to disable lock creation by using disableLuceneLocks
    system property.  This is useful for read-only media, such as CD-ROMs.
    (otis)

 4. Added id method to Hits to be able to access the index global id.
    Required for sorting options.
    (carlson)

 5. Added support for new range query syntax to QueryParser.jj.
    (briangoetz)

 6. Added the ability to retrieve HTML documents' META tag values to
    HTMLParser.jj.
    (Mark Harwood via otis)

 7. Modified QueryParser to make it possible to programmatically specify the
    default Boolean operator (OR or AND).
    (Péter Halácsy via otis)

 8. Made many search methods and classes non-final, per requests.
    This includes IndexWriter and IndexSearcher, among others.
    (cutting)

 9. Added class RemoteSearchable, providing support for remote
    searching via RMI.  The test class RemoteSearchableTest.java
    provides an example of how this can be used.  (cutting)

 10. Added PhrasePrefixQuery (and supporting MultipleTermPositions).  The
     test class TestPhrasePrefixQuery provides the usage example.
     (Anders Nielsen via otis)

 11. Changed the German stemming algorithm to ignore case while
     stripping. The new algorithm is faster and produces more equal
     stems from nouns and verbs derived from the same word.
     (gschwarz)

 12. Added support for boosting the score of documents and fields via
     the new methods Document.setBoost(float) and Field.setBoost(float).

     Note: This changes the encoding of an indexed value.  Indexes
     should be re-created from scratch in order for search scores to
     be correct.  With the new code and an old index, searches will
     yield very large scores for shorter fields, and very small scores
     for longer fields.  Once the index is re-created, scores will be
     as before. (cutting)

 13. Added new method Token.setPositionIncrement().

     This permits, for the purpose of phrase searching, placing
     multiple terms in a single position.  This is useful with
     stemmers that produce multiple possible stems for a word.

     This also permits the introduction of gaps between terms, so that
     terms which are adjacent in a token stream will not be matched by
     and exact phrase query.  This makes it possible, e.g., to build
     an analyzer where phrases are not matched over stop words which
     have been removed.

     Finally, repeating a token with an increment of zero can also be
     used to boost scores of matches on that token.  (cutting)

 14. Added new Filter class, QueryFilter.  This constrains search
     results to only match those which also match a provided query.
     Results are cached, so that searches after the first on the same
     index using this filter are very fast.

     This could be used, for example, with a RangeQuery on a formatted
     date field to implement date filtering.  One could re-use a
     single QueryFilter that matches, e.g., only documents modified
     within the last week.  The QueryFilter and RangeQuery would only
     need to be reconstructed once per day. (cutting)

 15. Added a new IndexWriter method, getAnalyzer().  This returns the
     analyzer used when adding documents to this index. (cutting)

 16. Fixed a bug with IndexReader.lastModified().  Before, document
     deletion did not update this.  Now it does.  (cutting)

 17. Added Russian Analyzer.
     (Boris Okner via otis)

 18. Added a public, extensible scoring API.  For details, see the
     javadoc for org.apache.lucene.search.Similarity.

 19. Fixed return of Hits.id() from float to int. (Terry Steichen via Peter).

 20. Added getFieldNames() to IndexReader and Segment(s)Reader classes.
     (Peter Mularien via otis)

 21. Added getFields(String) and getValues(String) methods.
     Contributed by Rasik Pandey on 2002-10-09
     (Rasik Pandey via otis)

 22. Revised internal search APIs.  Changes include:

       a. Queries are no longer modified during a search.  This makes
       it possible, e.g., to reuse the same query instance with
       multiple indexes from multiple threads.

       b. Term-expanding queries (e.g. PrefixQuery, WildcardQuery,
       etc.)  now work correctly with MultiSearcher, fixing bugs 12619
       and 12667.

       c. Boosting BooleanQuery's now works, and is supported by the
       query parser (problem reported by Lee Mallabone).  Thus a query
       like "(+foo +bar)^2 +baz" is now supported and equivalent to
       "(+foo^2 +bar^2) +baz".

       d. New method: Query.rewrite(IndexReader).  This permits a
       query to re-write itself as an alternate, more primitive query.
       Most of the term-expanding query classes (PrefixQuery,
       WildcardQuery, etc.) are now implemented using this method.

       e. New method: Searchable.explain(Query q, int doc).  This
       returns an Explanation instance that describes how a particular
       document is scored against a query.  An explanation can be
       displayed as either plain text, with the toString() method, or
       as HTML, with the toHtml() method.  Note that computing an
       explanation is as expensive as executing the query over the
       entire index.  This is intended to be used in developing
       Similarity implementations, and, for good performance, should
       not be displayed with every hit.

       f. Scorer and Weight are public, not package protected.  It now
       possible for someone to write a Scorer implementation that is
       not in the org.apache.lucene.search package.  This is still
       fairly advanced programming, and I don't expect anyone to do
       this anytime soon, but at least now it is possible.

       g. Added public accessors to the primitive query classes
       (TermQuery, PhraseQuery and BooleanQuery), permitting access to
       their terms and clauses.

     Caution: These are extensive changes and they have not yet been
     tested extensively.  Bug reports are appreciated.
     (cutting)

 23. Added convenience RAMDirectory constructors taking File and String
     arguments, for easy FSDirectory to RAMDirectory conversion.
     (otis)

 24. Added code for manual renaming of files in FSDirectory, since it
     has been reported that java.io.File's renameTo(File) method sometimes
     fails on Windows JVMs.
     (Matt Tucker via otis)

 25. Refactored QueryParser to make it easier for people to extend it.
     Added the ability to automatically lower-case Wildcard terms in
     the QueryParser.
     (Tatu Saloranta via otis)


1.2 RC6

 1. Changed QueryParser.jj to have "?" be a special character which
    allowed it to be used as a wildcard term. Updated TestWildcard
    unit test also. (Ralf Hettesheimer via carlson)

1.2 RC5

 1. Renamed build.properties to default.properties and updated
    the BUILD.txt document to describe how to override the
    default.property settings without having to edit the file. This
    brings the build process closer to Scarab's build process.
    (jon)

 2. Added MultiFieldQueryParser class. (Kelvin Tan, via otis)

 3. Updated "powered by" links. (otis)

 4. Fixed instruction for setting up JavaCC - Bug #7017 (otis)

 5. Added throwing exception if FSDirectory could not create diectory
    - Bug #6914 (Eugene Gluzberg via otis)

 6. Update MultiSearcher, MultiFieldParse, Constants, DateFilter,
    LowerCaseTokenizer javadoc (otis)

 7. Added fix to avoid NullPointerException in results.jsp
    (Mark Hayes via otis)

 8. Changed Wildcard search to find 0 or more char instead of 1 or more
    (Lee Mallobone, via otis)

 9. Fixed error in offset issue in GermanStemFilter - Bug #7412
    (Rodrigo Reyes, via otis)

 10. Added unit tests for wildcard search and DateFilter (otis)

 11. Allow co-existence of indexed and non-indexed fields with the same name
     (cutting/casper, via otis)

 12. Add escape character to query parser.
     (briangoetz)

 13. Applied a patch that ensures that searches that use DateFilter
     don't throw an exception when no matches are found. (David Smiley, via
     otis)

 14. Fixed bugs in DateFilter and wildcardquery unit tests. (cutting, otis, carlson)


1.2 RC4

 1. Updated contributions section of website.
    Add XML Document #3 implementation to Document Section.
    Also added Term Highlighting to Misc Section. (carlson)

 2. Fixed NullPointerException for phrase searches containing
    unindexed terms, introduced in 1.2RC3.  (cutting)

 3. Changed document deletion code to obtain the index write lock,
    enforcing the fact that document addition and deletion cannot be
    performed concurrently.  (cutting)

 4. Various documentation cleanups.  (otis, acoliver)

 5. Updated "powered by" links.  (cutting, jon)

 6. Fixed a bug in the GermanStemmer.  (Bernhard Messer, via otis)

 7. Changed Term and Query to implement Serializable.  (scottganyo)

 8. Fixed to never delete indexes added with IndexWriter.addIndexes().
    (cutting)

 9. Upgraded to JUnit 3.7. (otis)

1.2 RC3

 1. IndexWriter: fixed a bug where adding an optimized index to an
    empty index failed.  This was encountered using addIndexes to copy
    a RAMDirectory index to an FSDirectory.

 2. RAMDirectory: fixed a bug where RAMInputStream could not read
    across more than across a single buffer boundary.

 3. Fix query parser so it accepts queries with unicode characters.
    (briangoetz)

 4. Fix query parser so that PrefixQuery is used in preference to
    WildcardQuery when there's only an asterisk at the end of the
    term.  Previously PrefixQuery would never be used.

 5. Fix tests so they compile; fix ant file so it compiles tests
    properly.  Added test cases for Analyzers and PriorityQueue.

 6. Updated demos, added Getting Started documentation. (acoliver)

 7. Added 'contributions' section to website & docs. (carlson)

 8. Removed JavaCC from source distribution for copyright reasons.
    Folks must now download this separately from metamata in order to
    compile Lucene.  (cutting)

 9. Substantially improved the performance of DateFilter by adding the
    ability to reuse TermDocs objects.  (cutting)

10. Added IndexReader methods:
      public static boolean indexExists(String directory);
      public static boolean indexExists(File directory);
      public static boolean indexExists(Directory directory);
      public static boolean isLocked(Directory directory);
      public static void unlock(Directory directory);
    (cutting, otis)

11. Fixed bugs in GermanAnalyzer (gschwarz)


1.2 RC2, 19 October 2001:
 - added sources to distribution
 - removed broken build scripts and libraries from distribution
 - SegmentsReader: fixed potential race condition
 - FSDirectory: fixed so that getDirectory(xxx,true) correctly
   erases the directory contents, even when the directory
   has already been accessed in this JVM.
 - RangeQuery: Fix issue where an inclusive range query would
   include the nearest term in the index above a non-existant
   specified upper term.
 - SegmentTermEnum: Fix NullPointerException in clone() method
   when the Term is null.
 - JDK 1.1 compatibility fix: disabled lock files for JDK 1.1,
   since they rely on a feature added in JDK 1.2.

1.2 RC1 (first Apache release), 2 October 2001:
  - packages renamed from com.lucene to org.apache.lucene
  - license switched from LGPL to Apache
  - ant-only build -- no more makefiles
  - addition of lock files--now fully thread & process safe
  - addition of German stemmer
  - MultiSearcher now supports low-level search API
  - added RangeQuery, for term-range searching
  - Analyzers can choose tokenizer based on field name
  - misc bug fixes.

1.01b (last Sourceforge release), 2 July 2001
 . a few bug fixes
 . new Query Parser
 . new prefix query (search for "foo*" matches "food")

1.0, 2000-10-04

This release fixes a few serious bugs and also includes some
performance optimizations, a stemmer, and a few other minor
enhancements.

0.04 2000-04-19

Lucene now includes a grammar-based tokenizer, StandardTokenizer.

The only tokenizer included in the previous release (LetterTokenizer)
identified terms consisting entirely of alphabetic characters.  The
new tokenizer uses a regular-expression grammar to identify more
complex classes of terms, including numbers, acronyms, email
addresses, etc.

StandardTokenizer serves two purposes:

 1. It is a much better, general purpose tokenizer for use by
    applications as is.

    The easiest way for applications to start using
    StandardTokenizer is to use StandardAnalyzer.

 2. It provides a good example of grammar-based tokenization.

    If an application has special tokenization requirements, it can
    implement a custom tokenizer by copying the directory containing
    the new tokenizer into the application and modifying it
    accordingly.

0.01, 2000-03-30

First open source release.

The code has been re-organized into a new package and directory
structure for this release.  It builds OK, but has not been tested
beyond that since the re-organization.