Fuzzy search

Ispell

When mnoGoSearch is used with ispell support, all words are normalized. This allows finding different grammatical forms of the same words. During indexing, all words are stored "as is" in the database. During the search, all forms of the given keyword are selected and are taken into account. E.g. the search front-end will try to find the word "test" if "testing" or "tests" is given in the search query.

Flag V:
       E   > -E, IVE      # As in create> creative
      [^E] > IVE          # As in prevent > preventive
Flag *N:
       E   > -E, ION      # As in create > creation
       Y   > -Y, ICATION  # As in multiply > multiplication
     [^EY] > EN           # As in fall > fallen

wop/S
word/DGJMS
wordage/S
wordbook
wordily
wordless/P

Affix [lang] [charset] [ispell affixes file name]
Spell [lang] [charset] [ispell dictionary filename]

rare.dict:
----------
webmaster
intranet
.......
www
http
---------
			

Synonyms

Starting from mnoGoSearch version 3.2, synonyms-based fuzzy search is supported.

Synonyms files are installed into the etc/synonym subdirectory of mnoGoSearch's installation.

To enable synonyms, add search template commands like Synonym <filename> to search.htm, e.g.:

Synonym synonym/english.syn
Synonym synonym/russian.syn
  

Filenames are relative to the etc directory of mnoGoSearch's installation or absolute if they begin with /

Please feel free to send us your own synonyms lists at <devel@mnogosearch.org>.

Please use English synonym file as an example. In the beginning of the file the following two commands must be specified:

Language: en
Charset:  us-ascii

• Language - standard (ISO 639) two-letter language abbreviation.

• Charset - any charset supported by mnoGoSearch (see the Section called Character sets in Chapter 7).

The further lines contain synonyms, one group of synonyms per line. For example:

car auto automobile

All words written on the same line are considered to be equal. If you type one of the words in the search form, all other words from the same line are also searched.

An optional "Mode" command can be used inside a synonym file. It understands three values: "roundtrip", "oneway" and "return", with "roundtrip" value as default.

If "Mode: oneway" is specified then the words written on the same line are not considered as equal synonyms anymore. Only the leftmost word is expanded to other words. For example:

Mode: oneway
car auto automobile

If "Mode: return" is specified then all words are expanded only to the leftmost word, while the leftmost word itself is not expanded. For example:

Mode: return
car auto automobile

It's possible to use multiple "Mode" commands in the same synonym file and thus switch between "oneway", "return" and "roundtrip" style of synonyms for different lines:

Mode: roundtrip
colour color
Mode: oneway
car auto automobile

Since 3.2.34, mnoGoSearch also supports simple type of phrase synonyms:

president "george bush"

That means, if you type the word "president", the phrase "george bush" will also be searched.

Currently, word-to-phrase synonyms are only supported. Phrase-to-phrase and pharse-to-word synonyms do not work yet. I.e. if you type the phrase "george bush" (in quotes), the word "president" will not be searched. This feature will be implemented later.

Dehyphenation

Searching for both hyphenated and dehyphenated compound words at the same time is also possible. Refer to Dehyphenate command description for details.

Loading synonyms and word forms from SQL database

It is also possible to load synonyms or word forms from the database. Refer to SQLWordForms command description for details.

Dumping ispell data

To dump ispell data in a format suitable for loading into a SQL table for further use with SQLWordForms, copy all Affix and Spell commands from search.htm into indexer.conf then run "indexer -Edumpspell > dump.txt". indexer will write all word forms to the given "dump.txt" file in this format:

...
abate/abate
abate/abating
abate/abated
abate/abater
abate/abates
...

Use database specific tools or SQL syntax to load the newly created dump file into a SQL table, e.g. with MySQL:

CREATE TABLE spell
(
  word varchar(64) not null,
  form varchar(64) not null,
  key(word),
  key(form)
);
LOAD DATA INFILE 'dump.txt' INTO TABLE spell FIELDS TERMINATED BY '/';

Transliteration

Starting from 3.2.34, mnoGoSearch supports transliteration

Use tl=yes parameter to search.cgi to activate transliteration.

Currently, Latin-to-Cyrillic and Cyrillic-to-Latin transliteration is implemented. I.e. if you type a word in Latin script, a Cyrillic word with the same spelling is also searched, and visa versa.

Searching numbers

Starting from 3.2.36, mnoGoSearch supports numeric operators.

When UseNumericOperators is set to "yes", the "<" and ">" signs are treated as numeric comparison operators, e.g. "<100" finds all documents which have numbers less than 100 in their body or title or other sections according to the "wf" settings. Numeric operators can currently work only with the databases which support automatic comparison between VARCHAR and INT and do not require an explicit type cast. MySQL, PostgreSQL and SQLite are know to work.

If you specify two operators in the same search query, e.g. ">100 <200", then the documents having numbers more than 100 and, at the same time, having numbers less than 200 will be found. I.e. the above query does not strictly mean "a number between 100 and 200". A "between"-alike operator will be implemented later.

Accent insensitive search

When doing searches, mnoGoSearch relies on the database collation settings, thus accent insensitive searches will be available if the database software supports and is configured to use an accent insensitive collation.

CREATE DATABASE mnogosearch CHARACTER SET latin1 COLLATE latin1_general_ci;

CREATE TABLE bdict (
        word VARCHAR(64) CHARACTER SET ISO8859_1 NOT NULL COLLATE PT_BR,
        ...
);