S3 Writer Configuration

To enable S3 writes, you must create a writer.json file with the configuration parameters listed below. The sample configuration provided here outlines the necessary keys and their expected values.

writer.json

{
  "type": "PARQUET",
  "writer": {
    "normalization": false,
    "s3_bucket": "olake-s3-test",
    "s3_region": "ap-south-1",
    "s3_access_key": "xxxxxxxxxxxxxxxxxxxx",
    "s3_secret_key": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
    "s3_path": "/data"
  }
}

Configuration Key Details

Key	Description	Data Type	Probable Values
type	Specifies the output file format for writing data. Currently, only the "PARQUET" format is supported.	string	"PARQUET"
writer.normalization	Indicates whether data normalization (JSON flattening) should be applied before writing data to S3. Use true if you require normalized output, or false if not.	boolean	true or false (this example uses false)
writer.s3_bucket	The name of the Amazon S3 bucket where your output files will be stored. Ensure that the bucket exists and that you have proper access.	string	A valid S3 bucket name (e.g. "olake-s3-test")
writer.s3_region	The AWS region where the specified S3 bucket is hosted.	string	AWS region codes such as "ap-south-1", "us-west-2", etc.
writer.s3_access_key	The AWS access key used for authenticating S3 requests. This is typically a 20-character alphanumeric string.	string	A valid AWS access key
writer.s3_secret_key	The AWS secret key used for S3 authentication. This key is generally longer (often 40+ characters) and should be kept secure.	string	A valid AWS secret key
writer.s3_path	The specific path (or prefix) within the S3 bucket where data files will be written. This is typically a folder path that starts with a / (e.g. "/data").	string	A valid path string

info

1. The generated .parquet files use SNAPPY compression (Read more). Note that SNAPPY is no longer supported by S3 Select when performing queries.
2. OLake creates a test folder named olake_writer_test containing a single text file (.txt) with the content:

   S3 write test
   This is used to verify that you have the necessary permissions to write to S3.