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* replace exit with assert in test_single_page * improve save_raw_single_page docs option * More grammar fixes * "Built from" link in new tab * fix mistype * Example of include in docs * add anchor to meeting form * Draft of translation helper * WIP on translation helper * Replace some fa docs content with machine translation * add normalize-en-markdown.sh * normalize some en markdown * normalize some en markdown * admonition support * normalize * normalize * normalize * support wide tables * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * normalize * lightly edited machine translation of introdpection.md * lightly edited machhine translation of lazy.md * WIP on translation utils * Normalize ru docs * Normalize other languages * some fixes * WIP on normalize/translate tools * add requirements.txt * [experimental] add es docs language as machine translated draft * remove duplicate script * Back to wider tab-stop (narrow renders not so well)
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Dictionaries
A dictionary is a mapping (key -> attributes) that is convenient for various types of reference lists.
ClickHouse supports special functions for working with dictionaries that can be used in queries. It is easier and more efficient to use dictionaries with functions than a JOIN with reference tables.
NULL values can’t be stored in a dictionary.
ClickHouse supports:
- Built-in dictionaries with a specific set of functions.
- Plug-in (external) dictionaries with a set of functions.