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target-clickhouse

target-clickhouse is a Singer target for clickhouse.

Build with the Meltano Target SDK.

Configuration

Accepted Config Options

Setting Required Default Description
sqlalchemy_url False None The SQLAlchemy connection string for the ClickHouse database. Used if set, otherwise separate settings are used
driver False http Driver type
username False default Database user
password False None Username password
host False localhost Database host
port False 8123 Database connection port
database False default Database name
secure False 0 Should the connection be secure
verify False 1 Should secure connection need to verify SSL/TLS
engine_type False None The engine type to use for the table.
table_name False None The name of the table to write to. Defaults to stream name.
table_path False None The table path for replicated tables. This is required when using any of the replication engines. Check out the documentation for more information. Use $table_name to substitute the table name.
replica_name False None The replica_name for replicated tables. This is required when using any of the replication engines.
cluster_name False None The cluster to create tables in. This is passed as the clickhouse_cluster argument when creating a table. Documentation can be found here.
default_target_schema False None The default target database schema name to use for all streams.
optimize_after False 0 Run 'OPTIMIZE TABLE' after data insert
optimize_after False 0 Run 'OPTIMIZE TABLE' after data insert. Useful whentable engine removes duplicate rows.
load_method False TargetLoadMethods.APPEND_ONLY The method to use when loading data into the destination. append-only will always write all input records whether that records already exists or not. upsert will update existing records and insert new records. overwrite will delete all existing records and insert all input records.
stream_maps False None Config object for stream maps capability. For more information check out Stream Maps.
stream_map_config False None User-defined config values to be used within map expressions.
flattening_enabled False None 'True' to enable schema flattening and automatically expand nested properties.
flattening_max_depth False None The max depth to flatten schemas.

A full list of supported settings and capabilities is available by running: target-clickhouse --about

Configure using environment variables

This Singer target will automatically import any environment variables within the working directory's .env if the --config=ENV is provided, such that config values will be considered if a matching environment variable is set either in the terminal context or in the .env file.

Source Authentication and Authorization

Usage

You can easily run target-clickhouse by itself or in a pipeline using Meltano.

Executing the Target Directly

target-clickhouse --version
target-clickhouse --help
# Test using the "Carbon Intensity" sample:
tap-carbon-intensity | target-clickhouse --config /path/to/target-clickhouse-config.json

Developer Resources

Follow these instructions to contribute to this project.

Initialize your Development Environment

pipx install poetry
poetry install

Start the Clickhouse container

In order to run the tests locally, you must have a Docker daemon running on your host machine.

You can start the Clickhouse container by running:

./docker_run_clickhouse.sh

Create and Run Tests

Create tests within the tests subfolder and then run:

poetry run pytest

You can also test the target-clickhouse CLI interface directly using poetry run:

poetry run target-clickhouse --help

Testing with Meltano

Note: This target will work in any Singer environment and does not require Meltano. Examples here are for convenience and to streamline end-to-end orchestration scenarios.

Next, install Meltano (if you haven't already) and any needed plugins:

# Install meltano
pipx install meltano
# Initialize meltano within this directory
cd target-clickhouse
meltano install

Now you can test and orchestrate using Meltano:

# Test invocation:
meltano invoke target-clickhouse --version
# OR run a test `elt` pipeline with the Carbon Intensity sample tap:
meltano elt tap-carbon-intensity target-clickhouse

SDK Dev Guide

See the dev guide for more instructions on how to use the Meltano Singer SDK to develop your own Singer taps and targets.