ClickHouse/docs/en/engines/table-engines/integrations/s3.md
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---
toc_priority: 4
toc_title: S3
---
# S3 {#table_engines-s3}
This engine provides integration with [Amazon S3](https://aws.amazon.com/s3/) ecosystem. This engine is similar
to the [HDFS](../../../engines/table-engines/special/file.md#table_engines-hdfs) engine, but provides S3-specific features.
## Usage {#usage}
``` sql
ENGINE = S3(path, [aws_access_key_id, aws_secret_access_key,] format, structure, [compression])
```
**Input parameters**
- `path` — Bucket url with path to file. Supports following wildcards in readonly mode: *, ?, {abc,def} and {N..M} where N, M — numbers, `abc, def — strings.
- `format` — The [format](../../../interfaces/formats.md#formats) of the file.
- `structure` — Structure of the table. Format `'column1_name column1_type, column2_name column2_type, ...'`.
- `compression` — Parameter is optional. Supported values: none, gzip/gz, brotli/br, xz/LZMA, zstd/zst. By default, it will autodetect compression by file extension.
**Example:**
**1.** Set up the `s3_engine_table` table:
``` sql
CREATE TABLE s3_engine_table (name String, value UInt32) ENGINE=S3('https://storage.yandexcloud.net/my-test-bucket-768/test-data.csv.gz', 'CSV', 'name String, value UInt32', 'gzip')
```
**2.** Fill file:
``` sql
INSERT INTO s3_engine_table VALUES ('one', 1), ('two', 2), ('three', 3)
```
**3.** Query the data:
``` sql
SELECT * FROM s3_engine_table LIMIT 2
```
``` text
┌─name─┬─value─┐
│ one │ 1 │
│ two │ 2 │
└──────┴───────┘
```
## Implementation Details {#implementation-details}
- Reads and writes can be parallel
- Not supported:
- `ALTER` and `SELECT...SAMPLE` operations.
- Indexes.
- Replication.
**Globs in path**
Multiple path components can have globs. For being processed file should exist and match to the whole path pattern. Listing of files determines during `SELECT` (not at `CREATE` moment).
- `*` — Substitutes any number of any characters except `/` including empty string.
- `?` — Substitutes any single character.
- `{some_string,another_string,yet_another_one}` — Substitutes any of strings `'some_string', 'another_string', 'yet_another_one'`.
- `{N..M}` — Substitutes any number in range from N to M including both borders. N and M can have leading zeroes e.g. `000..078`.
Constructions with `{}` are similar to the [remote](../../../sql-reference/table-functions/remote.md) table function.
**Example**
1. Suppose we have several files in TSV format with the following URIs on HDFS:
- https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_1.csv
- https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_2.csv
- https://storage.yandexcloud.net/my-test-bucket-768/some_prefix/some_file_3.csv
- https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_1.csv
- https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_2.csv
- https://storage.yandexcloud.net/my-test-bucket-768/another_prefix/some_file_3.csv
2. There are several ways to make a table consisting of all six files:
<!-- -->
``` sql
CREATE TABLE table_with_range (name String, value UInt32) ENGINE = S3('https://storage.yandexcloud.net/my-test-bucket-768/{some,another}_prefix/some_file_{1..3}', 'CSV')
```
3. Another way:
``` sql
CREATE TABLE table_with_question_mark (name String, value UInt32) ENGINE = S3('https://storage.yandexcloud.net/my-test-bucket-768/{some,another}_prefix/some_file_?', 'CSV')
```
4. Table consists of all the files in both directories (all files should satisfy format and schema described in query):
``` sql
CREATE TABLE table_with_asterisk (name String, value UInt32) ENGINE = S3('https://storage.yandexcloud.net/my-test-bucket-768/{some,another}_prefix/*', 'CSV')
```
!!! warning "Warning"
If the listing of files contains number ranges with leading zeros, use the construction with braces for each digit separately or use `?`.
**Example**
Create table with files named `file-000.csv`, `file-001.csv`, … , `file-999.csv`:
``` sql
CREATE TABLE big_table (name String, value UInt32) ENGINE = S3('https://storage.yandexcloud.net/my-test-bucket-768/big_prefix/file-{000..999}.csv', 'CSV')
```
## Virtual Columns {#virtual-columns}
- `_path` — Path to the file.
- `_file` — Name of the file.
## S3-related settings {#settings}
The following settings can be set before query execution or placed into configuration file.
- `s3_max_single_part_upload_size` — Default value is `64Mb`. The maximum size of object to upload using singlepart upload to S3.
- `s3_min_upload_part_size` — Default value is `512Mb`. The minimum size of part to upload during multipart upload to [S3 Multipart upload](https://docs.aws.amazon.com/AmazonS3/latest/dev/uploadobjusingmpu.html).
- `s3_max_redirects` — Default value is `10`. Max number of S3 redirects hops allowed.
Security consideration: if malicious user can specify arbitrary S3 URLs, `s3_max_redirects` must be set to zero to avoid [SSRF](https://en.wikipedia.org/wiki/Server-side_request_forgery) attacks; or alternatively, `remote_host_filter` must be specified in server configuration.
### Endpoint-based settings {#s3endpointsettings}
The following settings can be specified in configuration file for given endpoint (which will be matched by exact prefix of a URL):
- `endpoint` — Mandatory. Specifies prefix of an endpoint.
- `access_key_id` and `secret_access_key` — Optional. Specifies credentials to use with given endpoint.
- `use_environment_credentials` — Optional, default value is `false`. If set to `true`, S3 client will try to obtain credentials from environment variables and Amazon EC2 metadata for given endpoint.
- `header` — Optional, can be speficied multiple times. Adds specified HTTP header to a request to given endpoint.
This configuration also applies to S3 disks in `MergeTree` table engine family.
Example:
```
<s3>
<endpoint-name>
<endpoint>https://storage.yandexcloud.net/my-test-bucket-768/</endpoint>
<!-- <access_key_id>ACCESS_KEY_ID</access_key_id> -->
<!-- <secret_access_key>SECRET_ACCESS_KEY</secret_access_key> -->
<!-- <use_environment_credentials>false</use_environment_credentials> -->
<!-- <header>Authorization: Bearer SOME-TOKEN</header> -->
</endpoint-name>
</s3>
**See Also**
- [Virtual columns](../../../engines/table-engines/index.md#table_engines-virtual_columns)
[Original article](https://clickhouse.tech/docs/en/operations/table_engines/s3/) <!--hide-->