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58 lines
1.6 KiB
Markdown
58 lines
1.6 KiB
Markdown
---
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navigation_title: "Keyword"
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mapped_pages:
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- https://www.elastic.co/guide/en/elasticsearch/reference/current/analysis-keyword-tokenizer.html
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---
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# Keyword tokenizer [analysis-keyword-tokenizer]
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The `keyword` tokenizer is a noop tokenizer that accepts whatever text it is given and outputs the exact same text as a single term. It can be combined with token filters to normalise output, e.g. lower-casing email addresses.
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## Example output [_example_output_10]
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```console
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POST _analyze
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{
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"tokenizer": "keyword",
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"text": "New York"
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}
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```
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The above sentence would produce the following term:
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```text
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[ New York ]
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```
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## Combine with token filters [analysis-keyword-tokenizer-token-filters]
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You can combine the `keyword` tokenizer with token filters to normalise structured data, such as product IDs or email addresses.
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For example, the following [analyze API](https://www.elastic.co/docs/api/doc/elasticsearch/operation/operation-indices-analyze) request uses the `keyword` tokenizer and [`lowercase`](/reference/text-analysis/analysis-lowercase-tokenfilter.md) filter to convert an email address to lowercase.
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```console
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POST _analyze
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{
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"tokenizer": "keyword",
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"filter": [ "lowercase" ],
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"text": "john.SMITH@example.COM"
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}
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```
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The request produces the following token:
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```text
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[ john.smith@example.com ]
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```
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## Configuration [_configuration_11]
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The `keyword` tokenizer accepts the following parameters:
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`buffer_size`
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: The number of characters read into the term buffer in a single pass. Defaults to `256`. The term buffer will grow by this size until all the text has been consumed. It is advisable not to change this setting.
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