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

​
max_temporary_columns

The maximum number of temporary columns that must be kept in RAM simultaneously when running a query, including constant columns. If a query generates more than the specified number of temporary columns in memory as a result of intermediate calculation, then an exception is thrown.
This setting is useful for preventing overly complex queries.
0 value means unlimited.

​
max_temporary_data_on_disk_size_for_query

The maximum amount of data consumed by temporary files on disk in bytes for all concurrently running queries. Possible values:
  • Positive integer.
  • 0 — unlimited (default)

​
max_temporary_data_on_disk_size_for_user

The maximum amount of data consumed by temporary files on disk in bytes for all concurrently running user queries. Possible values:
  • Positive integer.
  • 0 — unlimited (default)

​
max_temporary_non_const_columns

Like max_temporary_columns, the maximum number of temporary columns that must be kept in RAM simultaneously when running a query, but without counting constant columns.
Constant columns are formed fairly often when running a query, but they require approximately zero computing resources.
Last modified on July 23, 2026