v.22.11Improvement

Added allow_readonly Field to system.table_functions for Readonly Mode Support

Added new field allow_readonly in system.table_functions to allow using table functions in readonly mode. Resolves #42414 Implementation: * Added a new field allow_readonly to table system.table_functions. * Updated to use new field allow_readonly to allow using table functions in readonly mode. Testing: * Added a test for filesystem tests/queries/0_stateless/02473_functions_in_readonly_mode.sh Documentation: * Updated the english documentation for Table Functions. #42708 (SmitaRKulkarni).
Added a new allow_readonly field in system.table_functions to enable usage of table functions in readonly mode.

Why it matters

This feature allows users to execute table functions even when ClickHouse is running in readonly mode, addressing the limitation that previously prevented such operations. It improves usability by expanding the capability of table functions under readonly restrictions.

How to use it

Users can check the new allow_readonly field in system.table_functions to identify which table functions are permitted in readonly mode. Functions marked with allow_readonly = 1 are usable without disabling readonly mode.