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33 lines
1.8 KiB
Markdown
33 lines
1.8 KiB
Markdown
---
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toc_priority: 38
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toc_title: DICTIONARY
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---
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# CREATE DICTIONARY {#create-dictionary-query}
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Creates a new [external dictionary](../../../sql-reference/dictionaries/external-dictionaries/external-dicts.md) with given [structure](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md), [source](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-sources.md), [layout](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-layout.md) and [lifetime](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-lifetime.md).
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Syntax:
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``` sql
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CREATE DICTIONARY [IF NOT EXISTS] [db.]dictionary_name [ON CLUSTER cluster]
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(
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key1 type1 [DEFAULT|EXPRESSION expr1] [HIERARCHICAL|INJECTIVE|IS_OBJECT_ID],
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key2 type2 [DEFAULT|EXPRESSION expr2] [HIERARCHICAL|INJECTIVE|IS_OBJECT_ID],
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attr1 type2 [DEFAULT|EXPRESSION expr3],
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attr2 type2 [DEFAULT|EXPRESSION expr4]
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)
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PRIMARY KEY key1, key2
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SOURCE(SOURCE_NAME([param1 value1 ... paramN valueN]))
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LAYOUT(LAYOUT_NAME([param_name param_value]))
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LIFETIME({MIN min_val MAX max_val | max_val})
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```
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External dictionary structure consists of attributes. Dictionary attributes are specified similarly to table columns. The only required attribute property is its type, all other properties may have default values.
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`ON CLUSTER` clause allows creating dictionary on a cluster, see [Distributed DDL](../../../sql-reference/distributed-ddl.md).
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Depending on dictionary [layout](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-layout.md) one or more attributes can be specified as dictionary keys.
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For more information, see [External Dictionaries](../../../sql-reference/dictionaries/external-dictionaries/external-dicts.md) section.
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