ClickHouse

ClickHouse is an open-source, column-oriented database management system for online analytical processing (OLAP). It is built for speed at scale — running aggregations and analytical queries over billions of rows in real time.

The ClickHouse block connects to any ClickHouse deployment (ClickHouse Cloud or self-hosted) over the HTTP interface. Use it to run analytical queries, stream rows into tables, manage schemas, inspect system state, and execute arbitrary SQL — all from within a workflow.

Connection details

• Host — your ClickHouse hostname (e.g. your-instance.clickhouse.cloud or your server address).
• Port — the HTTP interface port. Use 8443 for HTTPS (ClickHouse Cloud) or 8123 for plain HTTP (self-hosted).
• Database / Username — default to default if not specified.
• Password — optional for unauthenticated local instances.
• Use HTTPS — keep enabled for any remote or Cloud instance.

Things to know

• UPDATE and DELETE are implemented as ClickHouse mutations (ALTER TABLE ... UPDATE/DELETE). Mutations run asynchronously in the background, so the affected row count is not returned immediately.
• ClickHouse is optimized for bulk inserts. Prefer batching many rows per insert over many single-row inserts.
• The connection host is validated to block private/internal addresses, so the block cannot reach localhost or internal-only hosts.

Usage Instructions

Integrate ClickHouse into the workflow. Query and insert data, manage databases and tables, inspect schemas, monitor mutations and running queries, manage partitions, and execute raw SQL over the ClickHouse HTTP interface.

Actions

clickhouse_query

Execute a SELECT query on a ClickHouse database

Input

Output

clickhouse_execute

Execute raw SQL (DDL, mutations, or queries) on a ClickHouse database

Input

Output

clickhouse_insert

Insert a row into a ClickHouse table

Input

Output

clickhouse_insert_rows

Insert multiple rows into a ClickHouse table

Input

Output

clickhouse_update

Update rows in a ClickHouse table via an ALTER TABLE ... UPDATE mutation

Input

Output

clickhouse_delete

Delete rows from a ClickHouse table via an ALTER TABLE ... DELETE mutation

Input

Output

clickhouse_list_databases

List all databases on a ClickHouse server

Input

Output

clickhouse_list_tables

List tables in the connected ClickHouse database

Input

Output

clickhouse_describe_table

Describe the columns of a ClickHouse table

Input

Output

clickhouse_show_create_table

Get the CREATE TABLE statement (DDL) for a ClickHouse table

Input

Output

clickhouse_count_rows

Count rows in a ClickHouse table, optionally filtered

Input

Output

clickhouse_introspect

Introspect a ClickHouse database to retrieve table structures, columns, and engines

Input

Output

clickhouse_create_database

Create a new database on a ClickHouse server

Input

Output

clickhouse_drop_database

Drop a database from a ClickHouse server

Input

Output

clickhouse_create_table

Create a new MergeTree-family table in ClickHouse

Input

Output

clickhouse_drop_table

Drop a table from a ClickHouse database

Input

Output

clickhouse_truncate_table

Remove all rows from a ClickHouse table

Input

Output

clickhouse_rename_table

Rename a ClickHouse table

Input

Output

clickhouse_optimize_table

Trigger a merge of table parts via OPTIMIZE TABLE

Input

Output

clickhouse_list_partitions

List active partitions for a ClickHouse table

Input

Output

clickhouse_drop_partition

Drop a partition from a ClickHouse table

Input

Output

clickhouse_list_mutations

List mutations (async ALTER UPDATE/DELETE) for the connected database

Input

Output

clickhouse_list_running_queries

List currently running queries on a ClickHouse server

Input

Output

clickhouse_kill_query

Kill a running query by its query ID

Input

Output

clickhouse_table_stats

Get row counts and on-disk size for tables in the connected database

Input

Output

clickhouse_list_clusters

List configured clusters, shards, and replicas

Input

Output