索引模块-同义词词元过滤器（Index Modules-Synonym Token Filter）

同义词词元过滤器

这个 同义词 词元过滤器能够轻松地处理同义词在分析过程。 同义词使用配置文件进行配置。 这里是一个例子:

{    "index" : {        "analysis" : {            "analyzer" : {                "synonym" : {                    "tokenizer" : "whitespace",                    "filter" : ["synonym"]                }            },            "filter" : {                "synonym" : {                    "type" : "synonym",                    "synonyms_path" : "analysis/synonym.txt"                }            }        }    }}

上面的配置 synonym 过滤器,一个路径 analysis/synonym.txt (相对于 config 位置)。 这个 synonym 分析器是然后配置过滤器。 额外的设置: ignore_case (默认为false),和 expand(默认为 true )。

这个 分词器 参数控制分词器,用于将分析同义词,默认了 whitespace 分词器。

截至elasticsearch 0.17.9 两个同义词格式支持:Solr,WordNet。

Solr同义词

下面是一个示例格式的文件:

# 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 podfoozball , foosballuniverse , cosmos# 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 barfoo => baz#is equivalent tofoo => foo bar, baz

您还可以定义同义词过滤器直接在配置文件(注意使用 同义词 而不是 synonyms_path（同义词配置文件路径） ):

{    "filter" : {        "synonym" : {            "type" : "synonym",            "synonyms" : [                "i-pod, i pod => ipod",                "universe, cosmos"            ]         }    }}

然而,建议定义大量的同义词集合在一个文件中使用synonyms_path。

WordNet同义词

同义词基于 WordNet 格式可以被声明使用 格式 :

{    "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)."            ]        }    }}

使用 同义词路径（synonyms_path） 定义一组 WordNet同义词 在一个文件里也是支持的。

 

Synonym Token Filter

The synonym token filter allows to easily handle synonyms during the analysis process. Synonyms are configured using a configuration file. Here is an example:

{    "index" : {        "analysis" : {            "analyzer" : {                "synonym" : {                    "tokenizer" : "whitespace",                    "filter" : ["synonym"]                }            },            "filter" : {                "synonym" : {                    "type" : "synonym",                    "synonyms_path" : "analysis/synonym.txt"                }            }        }    }}

The above configures a synonym filter, with a path of analysis/synonym.txt (relative to the config location). The synonym analyzer is then configured with the filter. Additional settings are: ignore_case (defaults to false), and expand (defaults to true).

The tokenizer parameter controls the tokenizers that will be used to tokenize the synonym, and defaults to the whitespace tokenizer.

As of elasticsearch 0.17.9 two synonym formats are supported: Solr, WordNet.

Solr synonyms

The 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 podfoozball , foosballuniverse , cosmos# 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 barfoo => baz#is equivalent tofoo => foo bar, baz

You can also define synonyms for the filter directly in the configuration file (note use ofsynonyms instead of synonyms_path):

{    "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.

WordNet synonyms

Synonyms based on WordNet format can be declared using format:

{    "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.