What is the limitation of using the Azure Search linked service as a sink in a copy data task?

The correct answer is that the JSON cannot contain complex data types like arrays. Azure Search is optimized for indexing and querying data, but it operates best with flat structures to ensure efficient searching and retrieval. When sending data to Azure Search through a linked service, any JSON documents that include complex data types, such as arrays or nested objects, face limitations and may not be indexed correctly. This restriction simplifies the indexing process and allows Azure Search to efficiently query the data it contains.

Having flat data structures aligns with the capabilities of Azure Search, enabling the service to perform better with the types of queries commonly used. While Azure Search does support some degree of structured data handling, sticking to flat JSON structures ensures compatibility and easier management of your indexed documents. This limitation reinforces the importance of understanding the data formats supported when designing data pipelines or integrations with Azure services.