How-To - ClickHouse

See how your table parts are spread between the block storage tier and object storage, and how much space each tier uses.

Cache the result of repeated SELECT queries to cut latency, and learn the size and entry limits that apply.

Set TTL rules that move data to object storage as it ages, and control age based deletion.

Add your service as a Grafana data source with the official ClickHouse or Altinity plugin, and build dashboards.

Open an interactive SQL session with the ClickHouse client over the native TLS port.

Connect from Go with clickhouse-go, over the native protocol or HTTPS.

Connect from Java using the ClickHouse JDBC driver over the HTTPS port.

Build the JDBC connection string for your service and open a connection from any JDBC client.

Connect from Node.js with the official client over HTTPS, including the settings that trip people up.

Connect from PHP with the smi2/phpclickhouse client over HTTPS.

Connect from Python with the native driver or plain HTTPS requests.

Copy tables from one service to another with remoteSecure, and use the right port to avoid a failed transfer.

Load reference data into memory as a dictionary to speed up lookups and joins.

Turn on tiered storage on a table so cold data moves to object storage automatically.

Read execution times, memory use and errors from system.query_log, and keep them beyond the one day retention.

Connect to your Managed ClickHouse® service from the ClickHouse client, Python, Go, Java, JDBC, Node.js, PHP or Grafana.

Inspect, resize, schedule maintenance for, fork and delete your Managed ClickHouse® service.

Inspect and drop the local cache that keeps frequently read object storage data close to the compute.

List the available ClickHouse versions and upgrade your service while it stays available, with only short interruptions.

Create, list and drop databases and tables, and learn which engine the service applies.

Create users, grant privileges per database and build roles, including the platform roles that already exist.

Pre-aggregate data at insert time with a materialized view writing to a destination table.

Run queries efficiently, and understand concurrency limits and routing on multi-node plans.

Restore a service by forking it from one of its daily backups.

Query object storage, HTTP endpoints and external databases directly in SQL, without moving the data.

Restrict who can reach your service with an IP filter, and protect it against accidental deletion.

Define reusable SQL functions to simplify repeated expressions in your queries.

Move partitions between block storage and object storage on demand, without waiting for TTL rules.

Read and write across all shards of a sharded plan with a distributed table.

Size the cache that keeps HNSW vector indexes in memory, and spot evictions that slow vector search.