mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 16:42:05 +00:00
133 lines
3.6 KiB
Markdown
133 lines
3.6 KiB
Markdown
---
|
|
toc_priority: 67
|
|
toc_title: NLP
|
|
---
|
|
|
|
# [experimental] Natural Language Processing functions {#nlp-functions}
|
|
|
|
!!! warning "Warning"
|
|
This is an experimental feature that is currently in development and is not ready for general use. It will change in unpredictable backwards-incompatible ways in future releases. Set `allow_experimental_nlp_functions = 1` to enable it.
|
|
|
|
## stem {#stem}
|
|
|
|
Performs stemming on a given word.
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
stem('language', word)
|
|
```
|
|
|
|
**Arguments**
|
|
|
|
- `language` — Language which rules will be applied. Must be in lowercase. [String](../../sql-reference/data-types/string.md#string).
|
|
- `word` — word that needs to be stemmed. Must be in lowercase. [String](../../sql-reference/data-types/string.md#string).
|
|
|
|
**Examples**
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT SELECT arrayMap(x -> stem('en', x), ['I', 'think', 'it', 'is', 'a', 'blessing', 'in', 'disguise']) as res;
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─res────────────────────────────────────────────────┐
|
|
│ ['I','think','it','is','a','bless','in','disguis'] │
|
|
└────────────────────────────────────────────────────┘
|
|
```
|
|
|
|
## lemmatize {#lemmatize}
|
|
|
|
Performs lemmatization on a given word. Needs dictionaries to operate, which can be obtained [here](https://github.com/vpodpecan/lemmagen3/tree/master/src/lemmagen3/models).
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
lemmatize('language', word)
|
|
```
|
|
|
|
**Arguments**
|
|
|
|
- `language` — Language which rules will be applied. [String](../../sql-reference/data-types/string.md#string).
|
|
- `word` — Word that needs to be lemmatized. Must be lowercase. [String](../../sql-reference/data-types/string.md#string).
|
|
|
|
**Examples**
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT lemmatize('en', 'wolves');
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─lemmatize("wolves")─┐
|
|
│ "wolf" │
|
|
└─────────────────────┘
|
|
```
|
|
|
|
Configuration:
|
|
``` xml
|
|
<lemmatizers>
|
|
<lemmatizer>
|
|
<lang>en</lang>
|
|
<path>en.bin</path>
|
|
</lemmatizer>
|
|
</lemmatizers>
|
|
```
|
|
|
|
## synonyms {#synonyms}
|
|
|
|
Finds synonyms to a given word. There are two types of synonym extensions: `plain` and `wordnet`.
|
|
|
|
With the `plain` extension type we need to provide a path to a simple text file, where each line corresponds to a certain synonym set. Words in this line must be separated with space or tab characters.
|
|
|
|
With the `wordnet` extension type we need to provide a path to a directory with WordNet thesaurus in it. Thesaurus must contain a WordNet sense index.
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
synonyms('extension_name', word)
|
|
```
|
|
|
|
**Arguments**
|
|
|
|
- `extension_name` — Name of the extension in which search will be performed. [String](../../sql-reference/data-types/string.md#string).
|
|
- `word` — Word that will be searched in extension. [String](../../sql-reference/data-types/string.md#string).
|
|
|
|
**Examples**
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT synonyms('list', 'important');
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌─synonyms('list', 'important')────────────┐
|
|
│ ['important','big','critical','crucial'] │
|
|
└──────────────────────────────────────────┘
|
|
```
|
|
|
|
Configuration:
|
|
``` xml
|
|
<synonyms_extensions>
|
|
<extension>
|
|
<name>en</name>
|
|
<type>plain</type>
|
|
<path>en.txt</path>
|
|
</extension>
|
|
<extension>
|
|
<name>en</name>
|
|
<type>wordnet</type>
|
|
<path>en/</path>
|
|
</extension>
|
|
</synonyms_extensions>
|
|
```
|