2020-04-03 13:23:32 +00:00
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---
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toc_priority: 40
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toc_title: Configuring an External Dictionary
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---
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2020-03-21 04:11:51 +00:00
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# Configuring an External Dictionary {#dicts-external-dicts-dict}
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2017-12-28 15:13:23 +00:00
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2020-02-20 06:31:06 +00:00
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If dictionary is configured using xml file, than dictionary configuration has the following structure:
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2017-12-28 15:13:23 +00:00
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2020-03-20 10:10:48 +00:00
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``` xml
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2017-12-28 15:13:23 +00:00
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<dictionary>
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<name>dict_name</name>
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2019-11-13 15:50:09 +00:00
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<structure>
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<!-- Complex key configuration -->
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</structure>
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2017-12-28 15:13:23 +00:00
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<source>
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<!-- Source configuration -->
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</source>
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<layout>
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<!-- Memory layout configuration -->
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</layout>
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<lifetime>
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<!-- Lifetime of dictionary in memory -->
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</lifetime>
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</dictionary>
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```
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2020-04-03 13:23:32 +00:00
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Corresponding [DDL-query](../../statements/create.md#create-dictionary-query) has the following structure:
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2019-11-13 15:50:09 +00:00
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2020-03-20 10:10:48 +00:00
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``` sql
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2019-11-13 15:50:09 +00:00
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CREATE DICTIONARY dict_name
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(
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... -- attributes
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)
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PRIMARY KEY ... -- complex or single key configuration
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SOURCE(...) -- Source configuration
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LAYOUT(...) -- Memory layout configuration
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LIFETIME(...) -- Lifetime of dictionary in memory
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```
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2020-03-21 04:11:51 +00:00
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- `name` – The identifier that can be used to access the dictionary. Use the characters `[a-zA-Z0-9_\-]`.
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2020-04-30 18:19:18 +00:00
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- [source](external-dicts-dict-sources.md) — Source of the dictionary.
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- [layout](external-dicts-dict-layout.md) — Dictionary layout in memory.
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- [structure](external-dicts-dict-structure.md) — Structure of the dictionary . A key and attributes that can be retrieved by this key.
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- [lifetime](external-dicts-dict-lifetime.md) — Frequency of dictionary updates.
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2018-10-16 10:47:17 +00:00
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2020-01-30 10:34:55 +00:00
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[Original article](https://clickhouse.tech/docs/en/query_language/dicts/external_dicts_dict/) <!--hide-->
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