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Recern Workspace · Documentation

ClickHouse

Workspace 0.3.0 adds ClickHouse diagnostics and a bounded, read-only SQL console. Compatibility checks cover ClickHouse 25.8 with password authentication, HTTP and HTTPS, directly and through SSH, including restricted accounts and reconnecting after cancellation.

Connect

Choose ClickHouse in New connection. Enter the server's HTTP port, usually 8123, or its HTTPS port, usually 8443 with TLS set to Required, verify certificate. The native-protocol port 9000 is not supported by this adapter. Set the database for table inspection and unqualified table names; it defaults to default.

An optional CA certificate file accepts a local PEM bundle, including a ~/ path, for a private certificate authority. The bundle becomes the connection's trust source. Certificate and hostname verification stay enabled; only the local path is saved. The bundle must be at most 1 MiB.

Both HTTP and HTTPS can pass through an SSH tunnel. HTTPS through SSH requires the database's DNS hostname so the certificate can be checked against the real server name. Connection and diagnostic-capability checks share a fifteen-second deadline.

Views and permissions

  • Overview shows query activity, running queries, stored rows, storage, tracked memory and findings. Counters include monitoring requests. The overview has a fifteen-second total deadline.
  • Queries lists up to 100 running queries, with elapsed time, reads, memory and SQL text.
  • Tables shows engines, row counts, storage and primary, sorting and partition keys in the selected database.
  • Indexes shows data-skipping indexes and their definitions.
  • Parts summarizes active parts by table and partition.
  • Merges shows current merge progress and resource use.
  • Mutations shows progress and reported failures.
  • Replicas shows replica state, queue size and lag when applicable.
  • Console runs read-only SQL with cancellation, history, saved queries and CSV/JSON export.

Other diagnostic lists are capped at 200 rows. Views depend on readable system tables and the server's capabilities. Unavailable views are omitted; an account may be able to query its application data without access to every diagnostic. A standalone server can legitimately have empty merge, mutation or replica views.

Read-only SQL console

For example, against the local fintech demo:

SELECT country, currency, count() AS payments, sum(amount) AS gross_amount
FROM payment_events
GROUP BY country, currency
ORDER BY country;

Run one statement at a time. Supported forms include SELECT, WITH, SHOW, DESCRIBE, EXPLAIN and EXISTS. Writes, administrative statements, SETTINGS, custom FORMAT, file output, and external or executable table functions are refused. The server also receives readonly=1 on every request. This boundary applies even if a saved connection has Safe Mode disabled.

Results are limited to 1,000 displayed rows, with a ten-second server limit, a fifteen-second HTTP deadline, a 256 MiB server memory limit, a 4 MiB server result limit and an 8 MiB transport limit including JSON overhead. The server must accept those request settings; Workspace reports an error rather than silently removing a limit.

Cancel targets only the app-generated ID of the active query. Large integers are preserved as strings. CSV and JSON export the displayed result; they do not run an unbounded database export. See query history, saved queries and export.