Engines

ClickHouse

Bobby Tables connects to ClickHouse through its HTTP interface and opens each connection in a SQL workspace that streams results and cancels queries by ID.

Where to find it

Action	How
Choose ClickHouse	`New connection`, `⌘N` (`Ctrl+N`), then `ClickHouse` under `Choose a provider`
Fill the form from a URL	`Use connection URL` with `clickhouse://` for HTTP or `clickhouses://` for HTTPS, then `Fill fields`
Defaults	Port `8123`, user `default`, database `default`

clickhouse+http:// and clickhouse+https:// URLs are accepted too.

Connecting

The form asks for Host, Port, User, Database (optional) and Password, and notes Uses ClickHouse HTTP with query IDs and pooled connections. New connections start with SSL mode set to Disable; Require encrypts without verification, Verify Ca checks the chain and Verify Full also checks the host name. Certificate files need an encrypted mode, and SSH and TLS covers tunnels. Open in read-only mode makes the app refuse writes and DDL with ClickHouse connection is read-only.

What works

Browse databases, tables, views, materialized views, engines, sizes and row estimates in the table grid.
Grid updates and deletes are disabled because ClickHouse keys do not identify a row, as described in Editing.
Create, rename, truncate and drop tables, and add, drop, rename or modify columns, in the Structure tab.
Snapshots are not available, so Create snapshot... does not appear.
The schema diagram is unavailable, and its button says This connection's driver does not report table relationships.
Format result columns with result directives.
Stop a running statement with Cancel, ⌘. (Ctrl+.), which sends KILL QUERY for its query ID.
Run Explain, ⌘⇧E (Ctrl+Shift+E), or Explain Analyze for the pipeline, in the SQL editor.

Engine notes

ClickHouse has no rollback guarantee, so scripts, DDL and imports run one statement at a time, and completed statements stay applied after a failure or a cancel. Committing a structure change opens SQL preview with that warning first. Run ALTER TABLE ... UPDATE or ALTER TABLE ... DELETE in the editor, and the app reports it only after the server finishes the mutation. Mutations need a MergeTree family table, and the server error is shown when an engine refuses one.

Good to know

Large integers and decimals arrive as exact text, and arrays, maps and tuples show as text.
Primary and sorting keys order data, so they are never used to identify a row.
The PostgreSQL page has a short video of opening a connection from Home.

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