Showing the (in)accuracy of sys.index_resumable_operations.

sys.index_resumable_operations.sql

DROP TABLE IF EXISTS dbo.DiningRoomTable;
GO
CREATE TABLE dbo.DiningRoomTable (Id INT IDENTITY(1,1) PRIMARY KEY CLUSTERED, Stuffing CHAR(1000));
INSERT INTO dbo.DiningRoomTable (Stuffing)
  SELECT 'Stuff'
  FROM sys.messages;
GO

CREATE INDEX IX_Stuffing ON dbo.DiningRoomTable(Stuffing)
  WITH (ONLINE = ON, RESUMABLE = ON);
GO

/* Run this immediately in another window: */
ALTER INDEX IX_Stuffing ON dbo.DiningRoomTable PAUSE;
GO

/* Check the percent complete: */
SELECT name, percent_complete FROM sys.index_resumable_operations;
GO

/* Double the number of rows in the table: */
INSERT INTO dbo.DiningRoomTable (Stuffing)
  SELECT 'Stuff'
  FROM sys.messages;
GO

/* Check the percent complete again: */
SELECT name, percent_complete FROM sys.index_resumable_operations;
GO

/* Triple 'em: */
INSERT INTO dbo.DiningRoomTable (Stuffing)
  SELECT 'Stuff'
  FROM sys.messages;
GO

/* Check the percent complete again: */
SELECT name, percent_complete FROM sys.index_resumable_operations;
GO