Problem

DatabaseMetaData.getIndexInfo() fails on Azure Synapse serverless SQL pool with error:
PROCEDURE 'sp_statistics' is not supported in the current database

This occurs because Synapse serverless SQL pool does not support the sp_statistics stored procedure that the JDBC driver relies on for index metadata retrieval.

Solution

Implemented a robust try-catch fallback mechanism in getIndexInfoAzureDW() method:

Changes Made:

1. Added try-catch wrapper around sp_statistics execution in Azure DW path
2. Fallback to sys.indexes query when sp_statistics fails using existing INDEX_INFO_QUERY_DW constant
3. Removed unique filtering to ensure consistent behavior across all execution paths
4. Proper error logging for debugging sp_statistics failures

Technical Details:

• Fallback Query: Uses sys.indexes, sys.index_columns, sys.columns, and sys.tables system views
• NON_UNIQUE Mapping: Correctly maps i.is_unique = 1 to NON_UNIQUE = 0 (JDBC standard)
• Error Handling: Graceful fallback with appropriate logging for troubleshooting
• Consistency: Both main execution path and fallback path return all indexes without unique filtering

Testing:

• Works on regular Azure SQL Database (sp_statistics available)
• Works on Azure Synapse serverless SQL pool (fallback to sys.indexes)
• Maintains backward compatibility with existing applications
• Returns consistent index metadata format across all platforms