To identify data skew in a dedicated SQL pool table, the most appropriate approach is to connect to the specific dedicated SQL pool (Pool1) and run the DBCC PDW_SHOWSPACEUSED command. This command provides detailed information about space usage and data distribution across distributions, which directly helps identify data skew by showing how data is distributed among the compute nodes.

Why Option B is optimal:

• DBCC PDW_SHOWSPACEUSED is specifically designed for Azure Synapse Analytics dedicated SQL pools to show space usage statistics
• It provides information about row counts and storage usage per distribution, allowing you to identify uneven data distribution
• You must connect to the dedicated SQL pool (Pool1) directly to run this command
• This approach follows Microsoft's recommended practices for analyzing data distribution in dedicated SQL pools

Why other options are less suitable:

• Option A: While sys.dm_pdw_nodes_db_partition_stats can provide partition statistics, connecting to the built-in pool (serverless SQL pool) to query this DMV against a dedicated pool is not supported. Serverless pools cannot access dedicated pool DMVs directly.
• Option C: sys.dm_pdw_node_status provides information about node health and status, not detailed data distribution or space usage metrics needed to identify data skew.
• Option D: sys.dm_pdw_sys_info contains system-level information about the SQL pool but doesn't provide the granular table-level distribution details required to measure data skew.

The DBCC PDW_SHOWSPACEUSED command is the most direct and reliable method for identifying data skew in dedicated SQL pool tables, as it specifically shows how data is distributed across the 60 distributions, which is fundamental to detecting and quantifying data skew.