For example, above DVM will count rows inserted by uncommited transactions. SQL Server 2008.

Open two queries in Managment Studio. In first query run

CREATE TABLE [testDVM](

[a] [int] NULL

) ON [PRIMARY]

GO

BEGIN TRAN;

INSERT testDVM

SELECT top(10) 1

FROM sys.all_objects;

Start the second query

DECLARE @RowCount1 INT;

SELECT @RowCount1=SUM(row_count)

FROM sys.dm_db_partition_stats AS ddps

WHERE ddps.index_id IN (0,1) AND ddps.object_id = OBJECT_ID('TestDVM');

SELECT Count(*) - @RowCount1 AS delta

FROM TestDVM;

return to the first one and run

INSERT testDVM

SELECT top(20) 2

FROM sys.all_objects;

COMMIT TRAN;

See the result of the second query. Apparently DVM was not waiting for the transaction to commit.