ch-iceberg

A set of ClickHouse user-defined functions to work with Apache Iceberg tables.

📦 Artifact: The Bundle

The output of the build process is distributed as a compressed archive called a bundle. This bundle includes everything needed to deploy and use the UDFs in ClickHouse.

📁 Bundle Contents

Each bundle contains:

• 🧩 Standalone binary implementing the native UDFs (compiled with ClickHouse compatibility)
• ⚙️ ClickHouse configuration files (.xml) to register each native UDF
• 📝 SQL files for SQL-based UDFs (used for lightweight functions where SQL outperforms compiled code)

📦 Bundle Usage

🛠️ Build the Bundle

make bundle              # Build for native execution

This will:

• Generate the bundle directory at tmp/bundle/
• Create a compressed archive at tmp/bundle.tar.gz

The internal file structure of the bundle reflects the default layout of a basic ClickHouse installation.
As a result, decompressing the archive at the root of a ClickHouse server filesystem should "just work" with no additional path configuration.

---

▶️ Run with clickhouse-local

clickhouse local \
    --log-level=debug \
    --path tmp/clickhouse \
    -- \
    --user_scripts_path="./tmp/bundle/var/lib/clickhouse/user_scripts" \
    --user_defined_executable_functions_config="./tmp/bundle/etc/clickhouse-server/*_function.*ml" \
    --user_defined_path="./tmp/bundle/var/lib/clickhouse/user_defined" \
    --send_logs_level=trace \
    --output_format_arrow_string_as_string=0

This runs ClickHouse in local mode using the provided config and a temporary storage path.