thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-21 23:21:59 +00:00
Code Issues Packages Projects Releases Wiki Activity

Examples moved to section end

Browse Source
This commit is contained in:
lehasm 2021-02-23 15:23:26 +03:00
parent d4ba07c5c6
commit 9e052ae178
1 changed files with 11 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
docs/en/interfaces/http.md
View File

@ -155,8 +155,7 @@ You can use compression to reduce network traffic when transmitting a large amou
You can use the internal ClickHouse compression format when transmitting data. The compressed data has a non-standard format, and you need `clickhouse-compressor` program to work with it. It is installed with the `clickhouse-client` package. To increase the efficiency of data insertion, you can disable server-side checksum verification by using the [http_native_compression_disable_checksumming_on_decompress](../operations/settings/settings.md#settings-http_native_compression_disable_checksumming_on_decompress) setting.
If you specify `compress=1` in the URL, the server will compress the data it sends to you.
If you specify `decompress=1` in the URL, the server will decompress the data which you pass in the `POST` method.
If you specify `compress=1` in the URL, the server will compress the data it sends to you. If you specify `decompress=1` in the URL, the server will decompress the data which you pass in the `POST` method.
You can also choose to use [HTTP compression](https://en.wikipedia.org/wiki/HTTP_compression). ClickHouse supports the following [compression methods](https://en.wikipedia.org/wiki/HTTP_compression#Content-Encoding_tokens):
@ -165,14 +164,22 @@ You can also choose to use [HTTP compression](https://en.wikipedia.org/wiki/HTTP
- `deflate`
- `xz`
To send a compressed `POST` request, append the request header `Content-Encoding: compression_method`. Example:
To send a compressed `POST` request, append the request header `Content-Encoding: compression_method`.
In order for ClickHouse to compress the response, enable compression with [enable_http_compression](../operations/settings/settings.md#settings-enable_http_compression) setting and append `Accept-Encoding: compression_method` header to the request. You can configure the data compression level in the [http_zlib_compression_level](../operations/settings/settings.md#settings-http_zlib_compression_level) setting for all compression methods.
!!! note "Note"
Some HTTP clients might decompress data from the server by default (with `gzip` and `deflate`) and you might get decompressed data even if you use the compression settings correctly.
**Examples**
``` bash
# Sending compressed data to the server
$ echo "SELECT 1" | gzip -c | \
curl -sS --data-binary @- -H 'Content-Encoding: gzip' 'http://localhost:8123/'
```
In order for ClickHouse to compress the response, enable compression with [enable_http_compression](../operations/settings/settings.md#settings-enable_http_compression) setting and append `Accept-Encoding: compression_method` header to the request. You can configure the data compression level in the [http_zlib_compression_level](../operations/settings/settings.md#settings-http_zlib_compression_level) setting for all compression methods.
``` bash
# Receiving compressed data from the server
$ curl -vsS "http://localhost:8123/?enable_http_compression=1" \
-H 'Accept-Encoding: gzip' --output result.gz -d 'SELECT number FROM system.numbers LIMIT 3'
$ zcat result.gz
@ -181,10 +188,6 @@ $ zcat result.gz
2
```
!!! note "Note"
Some HTTP clients might decompress data from the server by default (with `gzip` and `deflate`) and you might get decompressed data even if you use the compression settings correctly.
## Default Database {#default-database}
You can use the ‘database’ URL parameter or the ‘X-ClickHouse-Database’ header to specify the default database.