Perform Iceberg schema evolution by adding, renaming, and dropping columns without rewriting data

Steps

1. Add a new nullable column with ALTER TABLE my_catalog.db.events ADD COLUMN new_field STRING; Iceberg assigns it a new unique field ID so existing files are unaffected.
2. Rename a column with ALTER TABLE my_catalog.db.events RENAME COLUMN old_name TO new_name; the field ID remains stable so Parquet files written under the old name are still readable.
3. Drop a column with ALTER TABLE my_catalog.db.events DROP COLUMN deprecated_field; old files retain the bytes but the column will be excluded from reads.
4. Change a column type where safe widening is supported (e.g., int to bigint) with ALTER TABLE my_catalog.db.events ALTER COLUMN count TYPE bigint.
5. Verify the current schema and its history via SELECT * FROM my_catalog.db.events.history and SELECT * FROM my_catalog.db.events.snapshots to cross-reference schema IDs.