本地英文版地址: ../en/specify-analyzer.html
Specify an analyzeredit
Elasticsearch offers a variety of ways to specify built-in or custom analyzers:
-
By
textfield, index, or query - For index or search time
Keep it simple
The flexibility to specify analyzers at different levels and for different times is great… but only when it’s needed.
In most cases, a simple approach works best: Specify an analyzer for each
text field, as outlined in Specify the analyzer for a field.
This approach works well with Elasticsearch’s default behavior, letting you use the same analyzer for indexing and search. It also lets you quickly see which analyzer applies to which field using the get mapping API.
If you don’t typically create mappings for your indices, you can use index templates to achieve a similar effect.
How Elasticsearch determines the index analyzeredit
Elasticsearch determines which index analyzer to use by checking the following parameters in order:
-
The
analyzermapping parameter for the field. See Specify the analyzer for a field. -
The
analysis.analyzer.defaultindex setting. See Specify the default analyzer for an index.
If none of these parameters are specified, the
standard analyzer is used.
Specify the analyzer for a fieldedit
When mapping an index, you can use the analyzer mapping parameter
to specify an analyzer for each text field.
The following create index API request sets the
whitespace analyzer as the analyzer for the title field.
PUT my_index
{
"mappings": {
"properties": {
"title": {
"type": "text",
"analyzer": "whitespace"
}
}
}
}
Specify the default analyzer for an indexedit
In addition to a field-level analyzer, you can set a fallback analyzer for
using the analysis.analyzer.default setting.
The following create index API request sets the
simple analyzer as the fallback analyzer for my_index.
PUT my_index
{
"settings": {
"analysis": {
"analyzer": {
"default": {
"type": "simple"
}
}
}
}
}
How Elasticsearch determines the search analyzeredit
In most cases, specifying a different search analyzer is unnecessary. Doing so could negatively impact relevancy and result in unexpected search results.
If you choose to specify a separate search analyzer, we recommend you thoroughly test your analysis configuration before deploying in production.
At search time, Elasticsearch determines which analyzer to use by checking the following parameters in order:
-
The
analyzerparameter in the search query. See Specify the search analyzer for a query. -
The
search_analyzermapping parameter for the field. See Specify the search analyzer for a field. -
The
analysis.analyzer.default_searchindex setting. See Specify the default search analyzer for an index. -
The
analyzermapping parameter for the field. See Specify the analyzer for a field.
If none of these parameters are specified, the
standard analyzer is used.
Specify the search analyzer for a queryedit
When writing a full-text query, you can use the analyzer
parameter to specify a search analyzer. If provided, this overrides any other
search analyzers.
The following search API request sets the stop analyzer as
the search analyzer for a match query.
GET my_index/_search
{
"query": {
"match": {
"message": {
"query": "Quick foxes",
"analyzer": "stop"
}
}
}
}
Specify the search analyzer for a fieldedit
When mapping an index, you can use the search_analyzer mapping
parameter to specify a search analyzer for each text field.
If a search analyzer is provided, the index analyzer must also be specified
using the analyzer parameter.
The following create index API request sets the
simple analyzer as the search analyzer for the title field.
PUT my_index
{
"mappings": {
"properties": {
"title": {
"type": "text",
"analyzer": "whitespace",
"search_analyzer": "simple"
}
}
}
}
Specify the default search analyzer for an indexedit
When creating an index, you can set a default search
analyzer using the analysis.analyzer.default_search setting.
If a search analyzer is provided, a default index analyzer must also be
specified using the analysis.analyzer.default setting.
The following create index API request sets the
whitespace analyzer as the default search analyzer for the my_index index.
PUT my_index
{
"settings": {
"analysis": {
"analyzer": {
"default": {
"type": "simple"
},
"default_search": {
"type": "whitespace"
}
}
}
}
}