Extract Schema Once on Table Creation to Optimize Server Startup

Why it matters

This feature improves system performance and security by avoiding repeated schema extraction from local or external sources every time the ClickHouse server starts. It ensures that schema extraction is done only once at the time of table creation, reducing unnecessary I/O operations and potential security risks associated with reading from external files repeatedly.

How to use it

The feature is applied automatically when creating a table. Users do not need to change their existing workflow; the schema is extracted once at table creation and cached for subsequent server startups, preventing repeated reads from local or external files.