sys.pdw_nodes_pdw_physical_databases (Transact-SQL)

APPLIES TO: NoSQL Server NoAzure SQL Database NoAzure Synapse Analytics (SQL DW) YesParallel Data Warehouse

Contains a row for each physical database on a compute node. Aggregate physical database information to get detailed information about databases. To combine information, join the sys.pdw_nodes_pdw_physical_databases to the sys.pdw_database_mappings and sys.databases tables.

Column Name Data Type Description
database_id int The object ID for the database. Note that this value is not same as a database_id in the sys.databases (Transact-SQL) view.
physical_name sysname The physical name for the database on the Shell/Compute nodes. This value is same as a value in the physical_name column in the sys.pdw_database_mappings (Transact-SQL) view.
pdw_node_id int Unique numeric id associated with the node.

Examples: Parallel Data Warehouse

A. Returning

The following query returns the name and ID of each database in master, and the corresponding database name on each compute node.

SELECT D.database_id AS DBID_in_master, D.name AS UserDatabaseName,   
PD.pdw_node_id AS NodeID, DM.physical_name AS PhysDBName   
FROM sys.databases AS D  
JOIN sys.pdw_database_mappings AS DM  
    ON D.database_id = DM.database_id  
JOIN sys.pdw_nodes_pdw_physical_databases AS PD  
    ON DM.physical_name = PD.physical_name  
ORDER BY D.database_id, PD.pdw_node_ID;  

B. Using sys.pdw_nodes_pdw_physical_databases to gather detailed object information

The following query shows information about indexes and includes useful information about the database the objects belong to objects in the database.

SELECT D.name AS UserDatabaseName, D.database_id AS DBIDinMaster,  
DM.physical_name AS PhysDBName, PD.pdw_node_id AS NodeID,   
IU.object_id, IU.index_id, IU.user_seeks, IU.user_scans, IU.user_lookups, IU.user_updates  
FROM sys.databases AS D  
JOIN sys.pdw_database_mappings AS DM  
    ON D.database_id = DM.database_id  
JOIN sys.pdw_nodes_pdw_physical_databases AS PD  
    ON DM.physical_name = PD.physical_name  
JOIN sys.dm_pdw_nodes_db_index_usage_stats AS IU  
    ON PD.database_id = IU.database_id  
ORDER BY D.database_id, IU.object_id, IU.index_id, PD.pdw_node_ID;  

C. Using sys.pdw_nodes_pdw_physical_databases to determine the encryption state

The following query provides encryption state of the AdventureWorksPDW2012 database.

WITH dek_encryption_state AS   
(  
    SELECT ISNULL(db_map.database_id, dek.database_id) AS database_id, encryption_state  
    FROM sys.dm_pdw_nodes_database_encryption_keys AS dek  
        INNER JOIN sys.pdw_nodes_pdw_physical_databases AS node_db_map  
            ON dek.database_id = node_db_map.database_id AND dek.pdw_node_id = node_db_map.pdw_node_id  
        LEFT JOIN sys.pdw_database_mappings AS db_map  
            ON node_db_map .physical_name = db_map.physical_name  
        INNER JOIN sys.dm_pdw_nodes AS nodes  
            ON nodes.pdw_node_id = dek.pdw_node_id  
    WHERE dek.encryptor_thumbprint <> 0x  
)  
SELECT TOP 1 encryption_state  
       FROM  dek_encryption_state  
       WHERE dek_encryption_state.database_id = DB_ID('AdventureWorksPDW2012 ')  
       ORDER BY (CASE encryption_state WHEN 3 THEN -1 ELSE encryption_state END) DESC;  

See Also

SQL Data Warehouse and Parallel Data Warehouse Catalog Views
sys.databases (Transact-SQL)
sys.pdw_database_mappings (Transact-SQL)