If you need to update or append to your set of embeddings frequently (for example, new data arriving daily), what are best practices to maintain and update the search index without reprocessing everything?

To maintain and update a search index efficiently when new data arrives daily, focus on incremental updates, partial reindexing, and metadata management. Instead of rebuilding the entire index, process only new or modified data. Many vector databases (e.g., Pinecone, Milvus) support “upsert” operations, which allow inserting new embeddings or updating existing ones without reprocessing old data. For example, if you add 1,000 new documents daily, generate their embeddings and upsert them into the index. This avoids the computational cost of regenerating embeddings for all previous documents. Partitioning data into segments (e.g., by time) can also help: daily data might reside in a separate index partition, allowing you to update only the latest partition while querying across all partitions.

Handling deletions and updates requires careful metadata tracking. For deletions, mark records as inactive in the index using metadata flags rather than removing them immediately. During queries, filter out inactive entries. For updates, generate a new embedding for the modified document and replace the old entry (or mark it as stale). Some systems support versioned embeddings, where each update creates a new version while retaining the old one for rollback or audit purposes. For instance, a product database might update prices daily; instead of rebuilding the entire index, update only the affected product embeddings and adjust metadata like “last_updated_date.” This minimizes downtime and ensures the index remains available during updates.

Regular maintenance is critical for long-term efficiency. Over time, frequent incremental updates can fragment the index or leave stale data, impacting performance. Schedule periodic optimizations, such as merging small index segments or rebuilding specific partitions during off-peak hours. For example, a weekly job could reindex the oldest 10% of data to consolidate fragmented entries. Monitoring tools should track query latency and accuracy to detect degradation caused by index fragmentation or data drift. Automated scripts can trigger partial reindexing if metrics fall below thresholds. Combining these strategies ensures the index stays responsive and accurate without the overhead of full reprocessing.