Skip to main content
These settings are available in system.settings and are autogenerated from source.

​
implicit_select

Allow writing simple SELECT queries without the leading SELECT keyword, which makes it simple for calculator-style usage, e.g. 1 + 2 becomes a valid query. In clickhouse-local it is enabled by default and can be explicitly disabled.

​
implicit_table_at_top_level

If not empty, queries without FROM at the top level will read from this table instead of system.one. This is used in clickhouse-local for input data processing. The setting could be set explicitly by a user but is not intended for this type of usage. Subqueries are not affected by this setting (neither scalar, FROM, or IN subqueries). SELECTs at the top level of UNION, INTERSECT, EXCEPT chains are treated uniformly and affected by this setting, regardless of their grouping in parentheses. It is unspecified how this setting affects views and distributed queries. The setting accepts a table name (then the table is resolved from the current database) or a qualified name in the form of ‘database.table’. Both database and table names have to be unquoted - only simple identifiers are allowed.

​
implicit_transaction

If enabled and not already inside a transaction, wraps the query inside a full transaction (begin + commit or rollback)
Last modified on July 24, 2026