What are the supported data sources and file formats for the COPY (Transact-SQL) statement in Warehouse?

• A. Azure Data Lake Storage (ADLS) Gen2 and Azure Blob Storage, with PARQUET and CSV file formats.
• B. Azure Data Lake Storage (ADLS) Gen1 and Azure Blob Storage, with PARQUET and CSV file formats.
• C. Azure Data Lake Storage (ADLS) Gen2 and Azure Blob Storage, with ORC and CSV file formats.
• D. Azure Data Lake Storage (ADLS) Gen2 and Azure Data Lake Storage, with PARQUET and JSON file formats.

Answer: (A)

COPY in Warehouse loads data from external storage into the warehouse, using Azure storage endpoints and specific file formats. The supported data sources are Azure Data Lake Storage Gen2 and Azure Blob Storage, reflecting modern Azure storage options for big data workloads. ADLS Gen1 isn’t listed as a supported source for this operation, so it isn’t applicable here.

Among file formats, Parquet and CSV are supported by this COPY statement, giving you the efficiency of a columnar format (Parquet) and the simplicity of a plain text format (CSV). Formats like ORC or JSON aren’t indicated as supported for this particular COPY usage, so they aren’t valid choices in this context. Choosing the supported combination ensures the data can be parsed correctly and loaded efficiently.