v.21.6Improvement

Add external_storage_max_read_rows settings for MySQL engine and MaterializeMySQL data fetches

Official CH changelog text
Add settings external_storage_max_read_rows and external_storage_max_read_rows for MySQL table engine, dictionary source and MaterializeMySQL minor data fetches. #22697 (TCeason).
Add external_storage_max_read_rows and external_storage_max_read_rows settings for MySQL integration in ClickHouse to limit row fetch sizes.

Why it matters

These settings control the maximum number of rows fetched during minor data fetches from MySQL when using the MySQL table engine, dictionary source, and MaterializeMySQL. This helps to optimize performance and resource usage by preventing excessively large reads.

How to use it

Users can apply this feature by setting the external_storage_max_read_rows configuration options in their ClickHouse server settings or query context to limit the number of rows fetched from MySQL external storages during data refresh operations.

Related resources

PreviousNext