mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-17 05:03:20 +00:00
51 lines
1.6 KiB
Markdown
51 lines
1.6 KiB
Markdown
---
|
||
toc_priority: 40
|
||
toc_title: Configuring an External Dictionary
|
||
---
|
||
|
||
# Configuring an External Dictionary {#dicts-external-dicts-dict}
|
||
|
||
If dictionary is configured using xml file, than dictionary configuration has the following structure:
|
||
|
||
``` xml
|
||
<dictionary>
|
||
<name>dict_name</name>
|
||
|
||
<structure>
|
||
<!-- Complex key configuration -->
|
||
</structure>
|
||
|
||
<source>
|
||
<!-- Source configuration -->
|
||
</source>
|
||
|
||
<layout>
|
||
<!-- Memory layout configuration -->
|
||
</layout>
|
||
|
||
<lifetime>
|
||
<!-- Lifetime of dictionary in memory -->
|
||
</lifetime>
|
||
</dictionary>
|
||
```
|
||
|
||
Corresponding [DDL-query](../../../sql-reference/statements/create/dictionary.md) has the following structure:
|
||
|
||
``` sql
|
||
CREATE DICTIONARY dict_name
|
||
(
|
||
... -- attributes
|
||
)
|
||
PRIMARY KEY ... -- complex or single key configuration
|
||
SOURCE(...) -- Source configuration
|
||
LAYOUT(...) -- Memory layout configuration
|
||
LIFETIME(...) -- Lifetime of dictionary in memory
|
||
```
|
||
|
||
- `name` – The identifier that can be used to access the dictionary. Use the characters `[a-zA-Z0-9_\-]`.
|
||
- [source](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-sources.md) — Source of the dictionary.
|
||
- [layout](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-layout.md) — Dictionary layout in memory.
|
||
- [structure](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-structure.md) — Structure of the dictionary . A key and attributes that can be retrieved by this key.
|
||
- [lifetime](../../../sql-reference/dictionaries/external-dictionaries/external-dicts-dict-lifetime.md) — Frequency of dictionary updates.
|
||
|