--- 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. **See Also** - [Virtual columns](../../../engines/table-engines/index.md#table_engines-virtual_columns) ## 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 {#endpointsettings} 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. - `server_side_encryption_customer_key_base64` — Optional. If specified, required headers for accessing S3 objects with SSE-C encryption will be set. Example: ``` https://storage.yandexcloud.net/my-test-bucket-768/ ``` [Original article](https://clickhouse.tech/docs/en/operations/table_engines/s3/)