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Synonym Token Filter
editSynonym Token Filter
editThe synonym
token filter allows to easily handle synonyms during the
analysis process. Synonyms are configured using a configuration file.
Here is an example:
PUT /test_index { "settings": { "index" : { "analysis" : { "filter" : { "synonym" : { "type" : "synonym", "synonyms_path" : "analysis/synonym.txt", "tokenizer" : "whitespace" } }, "analyzer" : { "synonym" : { "tokenizer" : "whitespace", "filter" : ["synonym"] } } } } } }
We configure a |
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The |
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Two synonym formats are supported: Solr, WordNet.
Solr synonyms
editThe following is a sample format of the file:
# Blank lines and lines starting with pound are comments. # Explicit mappings match any token sequence on the LHS of "=>" # and replace with all alternatives on the RHS. These types of mappings # ignore the expand parameter in the schema. # Examples: i-pod, i pod => ipod, sea biscuit, sea biscit => seabiscuit # Equivalent synonyms may be separated with commas and give # no explicit mapping. In this case the mapping behavior will # be taken from the expand parameter in the schema. This allows # the same synonym file to be used in different synonym handling strategies. # Examples: ipod, i-pod, i pod foozball , foosball universe , cosmos lol, laughing out loud # If expand==true, "ipod, i-pod, i pod" is equivalent # to the explicit mapping: ipod, i-pod, i pod => ipod, i-pod, i pod # If expand==false, "ipod, i-pod, i pod" is equivalent # to the explicit mapping: ipod, i-pod, i pod => ipod # Multiple synonym mapping entries are merged. foo => foo bar foo => baz # is equivalent to foo => foo bar, baz
You can also define synonyms for the filter directly in the
configuration file (note use of synonyms
instead of synonyms_path
):
PUT /test_index { "settings": { "index" : { "analysis" : { "filter" : { "synonym" : { "type" : "synonym", "synonyms" : [ "i-pod, i pod => ipod", "universe, cosmos" ] } } } } } }
However, it is recommended to define large synonyms set in a file using
synonyms_path
, because specifying them inline increases cluster size unnecessarily.
WordNet synonyms
editSynonyms based on WordNet format can be
declared using format
:
PUT /test_index { "settings": { "index" : { "analysis" : { "filter" : { "synonym" : { "type" : "synonym", "format" : "wordnet", "synonyms" : [ "s(100000001,1,'abstain',v,1,0).", "s(100000001,2,'refrain',v,1,0).", "s(100000001,3,'desist',v,1,0)." ] } } } } } }
Using synonyms_path
to define WordNet synonyms in a file is supported
as well.