CHANGES

0.28

No changes, updated contact info

0.27

Fixed POD coverage test error

0.26

Fixed problem with re-indexing a document several times with
SQLite (rt.cpan.org #16247)

Stoplists now work with QueryParser

unscored_search() was returning internal document ids instead of keys

Fixed table_exists() in case schema name is prefixed to table name
in results of DBI->tables() call

0.25

New methods indexed() and last_indexed_key()

Removed a few stray print statements 

0.24

WARNING: indexes must be recreated, format has changed

Ability to reindex existing documents

New methods add(), begin_add(), commit_add() with support for arbitrary
keys and indexing of data from sources other than a database table

Made individual database drivers subclasses of DBIx::TextIndex::DBD
for easier porting. A new driver can override selected database-specific
methods instead of having to rewrite all methods.

Check for division by zero in _resolve_plural()

Bug fix for pathological case where only query term is a NOT term

0.23

 SQLite support

 Changed wildcard syntax slightly: a '?' character matches any
 single character.  A '+' at the end of a word behaves like the '?'
 character in previous versions, matching the singular or plural
 forms of the word.

 Wildcard characters '*' and '?' can now be used in the middle
 of a query term, as well as at the end of a query term.

 Added error messages error_wildcard_length and
 error_wildcard_expansion, collection table will be upgraded

 Added argument 'max_wildcard_term_expansion' to new().  This specifies
 the maximum number of words a wildcard term can expand to before
 throwing an exception.  The default is 30 words.   

 Fixed incorrect results for Okapi-scored results with wildcard terms

 Fixed segfault if position index structure is corrupted

 Fixed bug occurring when add_doc() is followed by search() on same
 instance of $index

0.22

WARNING: indexes must be recreated from scratch.
Rewrote proximity index code from scratch using XS. New index format
is faster, more compact, and scaleable. Flag proximity_index
now defaults to 1.

Removed legacy_tf_idf scoring method.

Fixed division-by-zero error with wildcard searches

Added support for PostgreSQL

0.21

Fixed bug where proximity search was case-sensitive instead of
case-insensitive

Fixed problem where some punctuation characters in query were
treated as query terms instead of ignoring the characters

0.20

Added inline fielded queries, e.g.:
$index->search( field1 => 'field2:this field3:"that phrase" foo bar' );
In previous version, this search could only be represented like this:
$index->search( field1 => 'foo bar',
                field2 => 'this',
                field3 => '"that phrase"');

The advantage of the new syntax is that fields can be combined in
arbitary boolean expressions, where previously only the union of the
fields was returned.  For example:

(field1:this OR field2:that) AND (field3:"foo bar" OR field1:foo)   

Wild and plural search bug fixes    

Turned proximity search back on, changed syntax. For example, to
find "foo" followed by "bar" with 0, 1 or 2 words between:
    "foo bar"~3 

0.19

Rewrote query parser.  Now we support nested subqueries in parentheses,
AND/OR/NOT operators, and existing '+/-' operators
(this OR that) AND (foo OR bar) +"this phrase" -"not this phrase"

Changed prefix query syntax slightly: '*' is now prefix operator, '?'
is plural operator:
  dog*  matches dog, dogs, dogma, dogmatic, dogmatically
  cat?  matches cat, cats

Rewrote critical loop of Okapi scoring as XSUB.  Search over large
collections is much faster.

0.18

Fixed bug where Okapi function did not score multiple fields

Tweaks to improve boolean search performance.

Added periodic flush of hash tables caches to save memory
in long-running instances.

Used a more compact represention of docweights, index needs to be
recreated.

0.17

Reduced memory usage by TermDocsCache

Implemented Okapi BM25 weighting function [S.E. Robertson et al., Google
for description] for scoring documents.  Pass scoring_method =>
'legacy_tfidf' to new() or search() to use older method.  Thanks to
the lucy project (http://www.seg.rmit.edu.au/lucy/) for inspiration.

Added docweights table to support Okapi BM25 scoring.  Indexes need to
be dropped and recreated.

Pass "update_commit_interval" to new() to control memory usage in
index updates.  As the index is built, postings lists are
built up in memory; this parameter controls the number of documents
held in memory before being flushed to the database.  Default is 20000.
To disable, pass 0, and all documents passed to add_doc() will
indexed in memory before writing to the database.

Fixed problem with inaccurate search results if multiple searches were
performed on a single instance while another instance was updating index.

0.16

Added XSUB pack_term_docs_append_vint to speed up _commit_docs when
adding new postings to existing compressed postings

0.15

WARNING: indexes will have to be recreated after upgrading to this version

Changed inverted list tables: renamed "docs" to "term_docs" and removed
redundant column "docs_vector".  Bit vectors are now built from postings
stored in term_docs column.  Total index size should be reduced
significantly with removal of docs_vector column.

Implemented DBIx::TextIndex::TermDocsCache to reduce database queries

Fixed bug where single word queries for high doc frequency terms would
return no results

0.14

Fixed memory leak in integer decoding

0.13

Changed format for inverted list postings to compressed binary
format.  Index sizes should be 50% smaller than with previous versions.
Implemented XS code for fast coding and decoding.  This format is similar
to the format in Lucene (http://jakarta.apache.org/lucene/).

Renamed 'freq_d' to 'docfreq_t'.

Bug fix: add_doc will only set bits in all_docs_vector if document
was actually added

UPGRADE warning, indexes will have to be rebuilt.

0.12

 Added _optimize_or_search(). If query contains just OR words,
 turn the rarest words into AND words to reduce result set size
 before scoring.  Practically, this makes queries behave more like
 "all of the words" instead of "any of the words," which seems to
 be what the average user expects.

 Changed all symbols 'occurence' to 'freq_d' (frequency of docs in
 entire collection that contain term)

 Multi-field queries will return the intersection of all fields
 instead of the union.

 Added method all_doc_ids().

 There is no longer any need to sort doc_ids before passing
 to add_doc().

 Added more tests. WARNING: MySQL database 'test' must be available
 on localhost for tests to succeed.

 UPGRADE WARNING: collection table format changed, new index table
 collection_all_docs_vector added, some field names have changed in
 inverted tables.  Any indexes created with 0.11 or earlier will have
 to be deleted and recreated.

 UPGRADE WARNING: all symbols with "document" have been renamed to
 "doc" for brevity.  Methods have also been renamed, e.g. add_document()
 is now add_doc().  The old method names will work, but are deprecated.

 Replaced option 'language' with 'charset'.  iso-8859-1 is the
 default charset.

 Added call to Text::Unaccent::unac_string (www.senga.org) to replace
 accented characters with plain ASCII equivalent.  Uses 'charset' option
 to determine mapping.

 UPGRADE WARNING: added structured exceptions using Exception::Class.
 Calls to search() now have to be wrapped with eval blocks to catch
 query exceptions.

0.11

Bug fix: HTML tags are now changed to a single space, instead of
empty string when indexing document. Prevents concatenation of words
in some cases.

0.10

Fixed collection table upgrade bug

0.09

Changed $MAX_WORD_LENGTH default to 20

Allow numbers to be indexed as words

Use HTML::Entities to decode entities in indexed documents, on by
default. Set option decode_html_entities to 0 to disable.

Use $dbh->tables to check for existence of tables (caution, may not
work in DBI > 1.30).

0.08

Bug fix: add_mask() was not inserting masks

0.07

UPGRADE WARNING: collection table format changed, use new method
$index->upgrade_collection_table() to recreate collection table. 
Calling initialize() method for a new collection will also upgrade
collection table. Index backup recommended.

Added error_ prefix to error message column names in collection table

Added version column to collection table

Added language column to collection table, removed czech_language column

UPGRADE WARNING: instead of new({ czech_language => 1}), use
new({ language => 'cz' })

Bug fix: _store_collection_info() error if stop lists are not used

unscored_search() will now return a scalar error message
if an error occurs in search

search() will croak if passed an invalid field name to search on

Added documentation for mask operations

0.06

    tripie's patch v2 updates:

    - a bug in document removing proccess related to incorrect
    'occurency' data updates when multi-field documents were removed,
    was fixed.  The methods remove_document() and _inverted_remove()
    were affected.

    - a bug related to wildcards in queries in form of "+word +next%"
    or "+word% +next%" was fixed

    - a bug related to "%" wildcards used while searching of
    multi-field documents was fixed

    - a bug related to stoplists and phrases that contain a
    non-stoplisted word together with a stoplisted word was fixed

    - a new full-featured solution of highligting of query words or
    patterns in content of resulting documents was added

    I've written a new module HTML::Highlight, that can be used
    either independently or together with DBIx::TextIndex. Its
    advantages include:

      - it makes highlighting very easy
      - takes phrases and wildcards into account
      - supports diacritics insensitive highlighting for iso-8859-2
        languages
      - takes HTML tags into account. That means when a user searches
        for for example 'font', than a FONT element in <FONT COLOR="red">
        does not get "highlighted".
		
    The module provides a very nice Google-like highlighting using
    different colors for different words or phrases.

    The module works together with DBIx::TextIndex using its new method
    html_highlight().

    The module can also be used to preview a context in which query
    words appear in resulting documents.
		
    - the old method highlight() was not changed nor removed for sake of
    compatibility with old code
	
    - I put a new 'html_search.cgi' script to examples/ to show how the new
    highlighting and context previewing works.
	  
    - the HTML::Highlight module can be found on CPAN - 
    http://www.cpan.org/authors/id/T/TR/TRIPIE/

    - the new highlighting solution has been documented in a new section
    of the documentation
	  
  tripie v1 changes:

    NOTE: tripie proximity index is replaced with newer compact index
    structure as of version 0.22
    added proximity indexing
      - based on positions of words in a document
      - by default it is disabled, activate it by new option "proximity_index"
      - very efficient for bigger documents, much worse for small ones
      - it's very big (approx. 20 bytes for each word)
      - allows fast proximity based searches in form of:
        ":2 some phrase" => matches "some nice phrase"
        ":1 some phrase" => matches only exact "some phrase"
        ":10 some phrase" => matches "some [1..9 words] phrase"
        defaults to ":1" when omitted
      - the proximity matches work only forwards, not backwards,
        that means:
        ":3 some phrase" does not match "phrase nice some" or "phrase some"

        NOTE: as of version 0.20, this syntax has changed:
        "some phrase"~3

    rewrote the word splitter and query parser
      - added support for czech language diacritics insensitive indexing
        and searching (option "czech_language")
	(note: changed option to "charset", pass value "iso-8859-2"
	to enable -dkoch)
        that is implemented by converting both the indexed data and
	the query from iso-8859-2 to ASCII

      - this can also be used for other iso-8859-2 based Slavic languages

      - the above is performed by my module "CzFast" that can
        be found on CPAN (my CPAN id is "TRIPIE"), and is optional

    added partial pattern matching using wildcards "%" or "*"
      - these wildcards can be used at end of a word to match all words
        that begin with that word, ie.

        the "%" character means "match any characters"

        car%	==> matches "car", "cars", "careful", "cartel", ....

        the "*" character means "match also the plural form"

        car*	==> matches only "car" or "cars"

      - added option "min_wildcard_length" to specify minimal length of a
        word base appearing before the "%" wildcard character to avoid
        selection of excessive amount of results

    added a database abstraction layer - all SQL queries were moved to
    separate module (see lib/ and the docs for new "db" option) and
    polished a bit for better maintainability and possible support of
    other SQL dialects

    added stoplists
      - some words that are too common (are present in almost every document)
	are not indexed and are removed from the search query before processing
	to avoid expensive processing of excessively huge result sets
      - user is notified when a search does not produce any results because
	some words he used in his query were stoplisted (no_results_stop)
      - stoplists can be easily localized or modified 
      - default is not to use any stoplist, one or more stoplists 
	can be selected using the "stoplist" option
      - stoplist data files are in lib/
      - english (en) and czech (cz) stoplists are included
      - more than one stoplist can be used

    added a facility to remove documents from the index - 
      check the documentation for new method "remove_document" for more info.
	
      There is no way to recover all the space taken by the documents that are
      being removed. This method manages to recover approx. 80% of the space.
	
      It's recommended to rebuild the index when you remove a
      significant amount of documents.

    added a facility to obtain some statistical information about the index -
      check the documentation for new method "stat"

    max_word_length, phrase_threshold and result_threshold are now configurable
    options

    added configuration options to customize/localize the error messages
    (no_results etc.)

    all new configuration options are properly stored in collection's data

    max_word_length limit now works much better - all words are stripped
    down to the maximum size before they are stored to the index,
    and also all query words are stripped down to the maximum word
    size before they are proccessed. Now when the max word length
    is set to, say, six and a user searches for for example
    "consciousness", all documents containing any words beginning
    with "consci" are returned Therefore the new max_word_length
    option is not a limit of a word size, but rather a
    "resolution" preference.  added some comments and occasionally
    corrected indentation

    documented the enhancements

    bugfix: when RaiseError was set on a DBI connection, then one
    query which only switched off PrintError to avoid some problems, failed

    note: the interface was not changed - old code using this module should
    run without any changes

    Thanks for this excellent module and please excuse my inferior English !

    Tomas Styblo, tripie@cpan.org

0.05

Added unscored_search() which returns a reference to an array of
doc_ids, without scores.  Should be much faster than scored search.

Added error handling in case _occurence() doesn't return a number.

0.04

Bug fix: add_document() will return if passed empty array ref instead
of producing error.

Changed _boolean_compare() and _phrase_search() so and_words and
phrases behave better in multiple-field searches. Result set for each
field is calculated first, then union of all fields is taken for
final result set.

Scores are scaled lower in _search().

0.03

Added example scripts in examples/.

0.02

Added or_mask_set.

0.01

Initial public release.  Should be considered beta, and methods may be
added or changed until the first stable release.