AWS SDK Version 3 for .NET
API Reference

AWS services or capabilities described in AWS Documentation may vary by region/location. Click Getting Started with Amazon AWS to see specific differences applicable to the China (Beijing) Region.

This operation is not supported by directory buckets.

This action filters the contents of an Amazon S3 object based on a simple structured query language (SQL) statement. In the request, along with the SQL expression, you must also specify a data serialization format (JSON, CSV, or Apache Parquet) of the object. Amazon S3 uses this format to parse object data into records, and returns only records that match the specified SQL expression. You must also specify the data serialization format for the response.

This functionality is not supported for Amazon S3 on Outposts.

For more information about Amazon S3 Select, see Selecting Content from Objects and SELECT Command in the Amazon S3 User Guide.


You must have the s3:GetObject permission for this operation. Amazon S3 Select does not support anonymous access. For more information about permissions, see Specifying Permissions in a Policy in the Amazon S3 User Guide.

Object Data Formats

You can use Amazon S3 Select to query objects that have the following format properties:

  • CSV, JSON, and Parquet - Objects must be in CSV, JSON, or Parquet format.

  • UTF-8 - UTF-8 is the only encoding type Amazon S3 Select supports.

  • GZIP or BZIP2 - CSV and JSON files can be compressed using GZIP or BZIP2. GZIP and BZIP2 are the only compression formats that Amazon S3 Select supports for CSV and JSON files. Amazon S3 Select supports columnar compression for Parquet using GZIP or Snappy. Amazon S3 Select does not support whole-object compression for Parquet objects.

  • Server-side encryption - Amazon S3 Select supports querying objects that are protected with server-side encryption.

    For objects that are encrypted with customer-provided encryption keys (SSE-C), you must use HTTPS, and you must use the headers that are documented in the GetObject. For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.

    For objects that are encrypted with Amazon S3 managed keys (SSE-S3) and Amazon Web Services KMS keys (SSE-KMS), server-side encryption is handled transparently, so you don't need to specify anything. For more information about server-side encryption, including SSE-S3 and SSE-KMS, see Protecting Data Using Server-Side Encryption in the Amazon S3 User Guide.

Working with the Response Body

Given the response size is unknown, Amazon S3 Select streams the response as a series of messages and includes a Transfer-Encoding header with chunked as its value in the response. For more information, see Appendix: SelectObjectContent Response.

GetObject Support

The SelectObjectContent action does not support the following GetObject functionality. For more information, see GetObject.

  • Range: Although you can specify a scan range for an Amazon S3 Select request (see SelectObjectContentRequest - ScanRange in the request parameters), you cannot specify the range of bytes of an object to return.

  • The GLACIER, DEEP_ARCHIVE, and REDUCED_REDUNDANCY storage classes, or the ARCHIVE_ACCESS and DEEP_ARCHIVE_ACCESS access tiers of the INTELLIGENT_TIERING storage class: You cannot query objects in the GLACIER, DEEP_ARCHIVE, or REDUCED_REDUNDANCY storage classes, nor objects in the ARCHIVE_ACCESS or DEEP_ARCHIVE_ACCESS access tiers of the INTELLIGENT_TIERING storage class. For more information about storage classes, see Using Amazon S3 storage classes in the Amazon S3 User Guide.

Special Errors

For a list of special errors for this operation, see List of SELECT Object Content Error Codes

The following operations are related to SelectObjectContent:


For .NET Core this operation is only available in asynchronous form. Please refer to SelectObjectContentAsync.

Namespace: Amazon.S3
Assembly: AWSSDK.S3.dll
Version: 3.x.y.z


public virtual SelectObjectContentResponse SelectObjectContent(
         SelectObjectContentRequest request


Type: Amazon.S3.Model.SelectObjectContentRequest

Container for the necessary parameters to execute the SelectObjectContent service method.

Return Value

The response from the SelectObjectContent service method, as returned by S3.

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

See Also