mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-12-01 12:01:58 +00:00

* CLICKHOUSE-4063: less manual html @ index.md

* CLICKHOUSE-4063: recommend markdown="1" in README.md

* CLICKHOUSE-4003: manually purge custom.css for now

* CLICKHOUSE-4064: expand <details> before any print (including to pdf)

* CLICKHOUSE-3927: rearrange interfaces/formats.md a bit

* CLICKHOUSE-3306: add few http headers

* Remove copy-paste introduced in #3392

* Hopefully better chinese fonts #3392

* get rid of tabs @ custom.css

* Apply comments and patch from #3384

* Add jdbc.md to ToC and some translation, though it still looks badly incomplete

* minor punctuation

* Add some backlinks to official website from mirrors that just blindly take markdown sources

* Do not make fonts extra light

* find . -name '*.md' -type f | xargs -I{} perl -pi -e 's//g' {}

* find . -name '*.md' -type f | xargs -I{} perl -pi -e 's/ sql/g' {}

* Remove outdated stuff from roadmap.md

* Not so light font on front page too

* Refactor Chinese formats.md to match recent changes in other languages

* Update some links on front page

* Remove some outdated comment

* Add twitter link to front page

* More front page links tuning

* Add Amsterdam meetup link

* Smaller font to avoid second line

* Add Amsterdam link to README.md

* Proper docs nav translation

* Back to 300 font-weight except Chinese

* fix docs build

* Update Amsterdam link

* remove symlinks

* more zh punctuation

* apply lost comment by @zhang2014

* Apply comments by @zhang2014 from #3417

* Remove Beijing link

* rm incorrect symlink

* restore content of docs/zh/operations/table_engines/index.md

* CLICKHOUSE-3751: stem terms while searching docs

* CLICKHOUSE-3751: use English stemmer in non-English docs too

* CLICKHOUSE-4135 fix

* Remove past meetup link

* Add blog link to top nav

* Add ContentSquare article link

* Add form link to front page + refactor some texts

* couple markup fixes

* minor

* Introduce basic ODBC driver page in docs

* More verbose 3rd party libs disclaimer

* Put third-party stuff into a separate folder

* Separate third-party stuff in ToC too

* Update links

* Move stuff that is not really (only) a client library into a separate page

* Add clickhouse-hdfs-loader link

* Some introduction for "interfaces" section

* Rewrite tcp.md

* http_interface.md -> http.md

* fix link

* Remove unconvenient error for now

* try to guess anchor instead of failing

* remove symlink

* Remove outdated info from introduction

* remove ru roadmap.md

* replace ru roadmap.md with symlink

* Update roadmap.md

* lost file

* Title case in toc_en.yml

* Sync "Functions" ToC section with en

* Remove reference to pretty old ClickHouse release from docs

* couple lost symlinks in fa

* Close quote in proper place

* Rewrite en/getting_started/index.md

* Sync en<>ru getting_started/index.md

* minor changes

* Some gui.md refactoring

* Translate DataGrip section to ru

* Translate DataGrip section to zh

* Translate DataGrip section to fa

* Translate DBeaver section to fa

* Translate DBeaver section to zh

* Split third-party GUI to open-source and commercial

* Mention some RDBMS integrations + ad-hoc translation fixes

* Add rel="external nofollow" to outgoing links from docs

* Lost blank lines

* Fix class name

* More rel="external nofollow"

* Apply suggestions by @sundy-li

* Mobile version of front page improvements

* test

* test 2

* test 3

* Update LICENSE

* minor docs fix

* Highlight current article as suggested by @sundy-li

* fix link destination

* Introduce backup.md (only "en" for now)

* Mention INSERT+SELECT in backup.md

* Some improvements for replication.md

* Add backup.md to toc

* Mention clickhouse-backup tool

* Mention LightHouse in third-party GUI list

* Introduce interfaces/third-party/proxy.md

* Add clickhouse-bulk to proxy.md

* Major extension of integrations.md contents

* fix link target

* remove unneeded file

* better toc item name

* fix markdown

* better ru punctuation

* Add yet another possible backup approach

* Simplify copying permalinks to headers

* Support non-eng link anchors in docs + update some deps

* Generate anchors for single-page mode automatically

* Remove anchors to top of pages

* Remove anchors that nobody links to

* build fixes

* fix few links

* restore css

* fix some links

* restore gifs

* fix lost words

* more docs fixes

* docs fixes

* NULL anchor

* update urllib3 dependency

* more fixes

* Remove excessive content from print version

* Try short license again

* Back to long license for now

* Introduce anchor integrity checks for single-page docs

* Add --save-raw-single-page option to build.py (helps to debug incorrect anchors)

* fix kafka engine links

* fix one class of broken anchors

* fix some broken links

* Add https://github.com/hatarist/clickhouse-cli to third-party section (in gui.md for now, maybe will add cli.md later)

* fix one more class of links to nowhere

* less duplicate anchors

* get rid of weird anchors

* fix anchor

* fix link

* fix couple links

2018-12-18 14:32:08 +03:00

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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.

Original article

752 B Raw Blame History

Dictionaries

752 B

Raw Blame History