Glossary ​

Database ​

A named server database, or a file-backed or in-memory database opened by an embedded application. A native session selects a managed database with USE.

Connection and session ​

A connection owns SQL and transaction state. A native session lasts for the connection; an HTTP session lasts for one request. Temporary objects and uncommitted changes belong to that scope.

Namespace ​

A connection's main, temp or attached database name. A namespace qualifies a table within a connection. It is distinct from managed server database selection.

Statement and request ​

A statement is one parsed SQL operation. A request can contain several statements and has one query ID. Request limits can span all of those statements.

Format ​

A named encoding that writes result rows, reads INSERT rows, or both. CoordinatorDB format names use snake_case. Each format documents its supported directions and options.

Database setting and format setting ​

A database setting is stored with the database and managed by SET or its documented alternative. A format setting applies to one statement through SETTINGS and is not persisted.

System catalog ​

The server's system relations expose database metadata, settings, functions, formats, active requests and history. Qualify them with system..

Query log and diagnostic log ​

The query log is structured request history available as system.query_log. The diagnostic log contains service messages and errors. These are separate interfaces with different fields and uses.