Redshift Bulk Loader transform Icon Redshift Bulk Loader

Description

The Redshift Bulk Loader transform loads data from Apache Hop to AWS Redshift using the COPY command.

make sure your target Redshift table has a layout that is compatible with Parquet data types, e.g. use int8 instead of int4 data types.
binary stream fields are written as lowercase hex (no \x prefix), which is what Redshift COPY expects for VARBYTE.

Supported Engines

Hop Engine

Supported

Single Threaded

Supported

Native Spark

Supported

Beam Spark

Maybe Supported

Beam Flink

Maybe Supported

Beam Dataflow

Maybe Supported

The Redshift Bulk Loader is linked to the database type. It will fetch the JDBC driver from the hop/lib/jdbc folder.

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General Options

Option Description

Transform name

Name of the transform.

Connection

Name of the database connection on which the target table resides.

Target schema

The name of the target schema to write data to.

Target table

The name of the target table to write data to.

AWS Authentication

choose which authentication method to use with the COPY command. Supported options are Inherit from connection, Credentials and IAM Role.

  • Inherit from connection takes the AWS credentials from the Redshift connection selected above, so they only have to be configured in one place. The connection must use one of its IAM authentication options; one that signs in with a database user and password has no AWS credentials to lend. A connection pointing at a named profile or at the AWS default credentials chain is resolved when the pipeline runs, and a session token is passed along when the resulting credentials are temporary.

  • check the Key-based access control for more information on the Credentials option.

  • check the IAM Role docs for more information on the IAM Role option.

Use AWS system variables

(Credentials only!) pick up the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY values from your operating system’s environment variables.

AWS_ACCESS_KEY_ID

(if Credentials is selected and Use AWS system variables is unchecked) specify a value or variable for your AWS_ACCESS_KEY_ID.

AWS_SECRET_ACCESS_KEY

(if Credentials is selected and Use AWS system variables is unchecked) specify a value or variable for your AWS_SECRET_ACCESS_KEY.

IAM Role

(if IAM Role is selected) specify the IAM Role to use, in the syntax arn:aws:iam::<aws-account-id>:role/<role-name>

Truncate table

Truncate the target table before loading data.

Truncate on first row

Truncate the target table before loading data, but only when a first data row is received (will not truncate when a pipeline runs an empty stream (0 rows)).

Specify database fields

Specify the database and stream fields mapping

Main Options

Option Description

Stream to S3 CSV

write the current pipeline stream to a CSV file in an S3 bucket before performing the COPY load.

Load from existing file

do not stream the contents of the current pipeline, but perform the COPY load from a pre-existing file in S3. Suppoorted formats are CSV (comma delimited) and Parquet.

Copy into Redshift from existing file

path to the file in S3 to COPY load the data from.

The staging file

When Stream to S3 CSV is enabled the transform writes the CSV named under Copy into Redshift from file name/path itself, and creates the folder it goes in when that does not exist yet. This matters on S3, where a prefix only exists for as long as an object sits under it: a brand new path would otherwise be refused before a single row was written.

JSON and SUPER columns

A JSON field is written to the CSV file enclosed and escaped, the same as any text that could otherwise break the row — JSON is full of commas and quotes, and Apache Hop pretty prints it across several lines by default.

COPY parses the field into a real SUPER object, so JSON_TYPEOF(payload) returns object once the value has loaded.

Two things surprise people when reading it back:

  • payload::varchar on a SUPER object is NULL. Use JSON_SERIALIZE(payload) to get the JSON text.

  • Redshift folds unquoted SUPER attribute names to lower case unless enable_case_sensitive_super_attribute is on, so payload.myField does not match a camelCase key — and quoting the attribute does not help while that setting is off.

Addressing the value as text sidesteps both:

SELECT JSON_EXTRACT_PATH_TEXT(JSON_SERIALIZE(payload), 'myField') FROM my_table;

Dates and timestamps

Date and timestamp fields are written to the CSV file as ISO 8601 with milliseconds, yyyy-MM-dd HH:mm:ss.SSS, and the COPY statement declares DATEFORMAT AS 'auto' and TIMEFORMAT AS 'auto' to read them back. auto is used because the explicit TIMEFORMAT patterns have no token for fractional seconds.

An Apache Hop Date carries a time of day just as a Timestamp does, so both are written whole and the target column decides what to keep: a TIMESTAMP column keeps the time, a DATE column truncates it.

Database fields

Map the current stream fields to the Redshift table’s columns.