From 64a431ae8b026bde8ccda498356482457eb5b6a1 Mon Sep 17 00:00:00 2001
From: Olga Revyakina <revolg@yandex-team.ru>
Date: Mon, 28 Sep 2020 05:59:01 +0300
Subject: [PATCH] Custom settings docs in english.

---
 .../settings.md                               | 14 ++++++++
 docs/en/operations/settings/index.md          | 26 ++++++++++++++
 .../functions/other-functions.md              | 36 +++++++++++++++++++
 3 files changed, 76 insertions(+)

diff --git a/docs/en/operations/server-configuration-parameters/settings.md b/docs/en/operations/server-configuration-parameters/settings.md
index ee0373c70b4..fc150ee551d 100644
--- a/docs/en/operations/server-configuration-parameters/settings.md
+++ b/docs/en/operations/server-configuration-parameters/settings.md
@@ -66,6 +66,20 @@ If no conditions met for a data part, ClickHouse uses the `lz4` compression.
 </compression>
 ```
 
+## custom_settings_prefixes {#custom_settings_prefixes}
+
+List of prefixes for [custom settings](../../operations/settings/index.md#custom_settings). The prefixes must be separated with commas.
+
+**Example**
+
+```xml
+<custom_settings_prefixes>custom_</custom_settings_prefixes>
+```
+
+**See Also**
+
+-   [Custom settings](../../operations/settings/index.md#custom_settings)
+
 ## default\_database {#default-database}
 
 The default database.
diff --git a/docs/en/operations/settings/index.md b/docs/en/operations/settings/index.md
index 59394d77b11..cd483694521 100644
--- a/docs/en/operations/settings/index.md
+++ b/docs/en/operations/settings/index.md
@@ -28,4 +28,30 @@ Ways to configure settings, in order of priority:
 
 Settings that can only be made in the server config file are not covered in this section.
 
+## Custom Settings {#custom_settings}
+
+In addition to the common [settings](../../operations/settings/settings.md), users can define custom settings. 
+
+A custom setting name must begin with one of predefined prefixes. The list of these prefixes must be declared in the [custom_settings_prefixes](../../operations/server-configuration-parameters/settings.md#custom_settings_prefixes) parameter in the server configuration file.
+
+```xml
+<custom_settings_prefixes>custom_</custom_settings_prefixes>
+```
+
+To define a custom setting use `SET` command:
+
+```sql
+SET custom_a = 123;
+```
+
+To get the current value of a custom setting use `getSetting()` function:
+
+```sql
+SELECT getSetting('custom_a');    
+```
+
+**See Also**
+
+-   [Server Configuration Settings](../../operations/server-configuration-parameters/settings.md)
+
 [Original article](https://clickhouse.tech/docs/en/operations/settings/) <!--hide-->
diff --git a/docs/en/sql-reference/functions/other-functions.md b/docs/en/sql-reference/functions/other-functions.md
index 1c059e9f97b..3d06bbfff9e 100644
--- a/docs/en/sql-reference/functions/other-functions.md
+++ b/docs/en/sql-reference/functions/other-functions.md
@@ -1491,4 +1491,40 @@ Result:
 
 ```
 
+## getSetting {#getSetting}
+
+Returns the current value of a [custom setting](../../operations/settings/index.md#custom_settings).
+
+**Syntax** 
+
+```sql
+getSetting('custom_setting');    
+```
+
+**Parameter** 
+
+-   `custom_setting` — The setting name. [String](../../sql-reference/data-types/string.md).
+
+**Returned value**
+
+-   The setting current value.
+
+**Example**
+
+```sql
+SET custom_a = 123;
+SELECT getSetting('custom_a');    
+```
+
+**Result**
+
+```
+123
+```
+
+**See Also** 
+
+-   [Custom Settings](../../operations/settings/index.md#custom_settings)
+
+
 [Original article](https://clickhouse.tech/docs/en/query_language/functions/other_functions/) <!--hide-->