min_external_* session settings

These settings are available in system.settings and are autogenerated from the ClickHouse snapshot.

min_external_table_block_size_bytes

Squash blocks passed to the external table to a specified size in bytes, if blocks are not big enough.

min_external_table_block_size_rows

Squash blocks passed to external table to specified size in rows, if blocks are not big enough.