CockroachDB has enhanced its bulk data ingestion and index backfilling processes to ensure Multi-Version Concurrency Control (MVCC) compliance, which is critical for maintaining data consistency in distributed systems. Traditionally, bulk operations like schema changes and index backfills bypassed regular transaction processing and directly wrote data to storage, potentially violating MVCC invariants. To address this, CockroachDB now mandates that AddSSTable operations write data at current timestamps to uphold MVCC principles, avoiding issues like stale reads. This change necessitated redesigning the index backfill process, originally reliant on AddSSTable's ability to write at previous timestamps. The new approach involves using a temporary index to capture concurrent writes during backfills, ensuring the main index remains consistent without overwriting newer data. This method effectively separates ongoing transactional writes from bulk backfill operations, maintaining data integrity and consistency across distributed nodes. The transformation ensures that index backfills are compatible with MVCC, enabling robust and reliable schema changes within CockroachDB's distributed database environment.