SQL Server Profiler offers an Event Class called Progress Report: Online Index Operation.
Below is a screen shot of the SQL Server Profiler output when a Clustered and Non-Clustered index is rebuilt online i.e.
USE [database_1] GO ALTER INDEX ALL ON [dbo].[Table_1] REBUILD WITH (ONLINE = ON) GO
click on the image to enlarge
The Stage 1 and Stage 2 references in the EventSubClass column may appear a bit confusing. The stages are explained here, along with the meaning of the other columns.
If for example only the Non-Clustered index was rebuilt online then only Stage 1 is shown in the output as follows i.e.
USE [database_1] GO ALTER INDEX [nci] ON [dbo].[Table_1] REBUILD WITH (ONLINE = ON) GO
click on the image to enlarge
Unfortunately there is not an estimate of when the rebuild will complete included in profiler and the below query will always show 0 percent complete. Currently only ALTER INDEX REORGANIZE will show the estimated percent completed.
SELECT text,start_time,percent_complete FROM sys.dm_exec_requests er CROSS APPLY sys.dm_exec_sql_text(er.sql_handle) WHERE 1=1 AND command = 'ALTER INDEX'
If the rebuild is taking a really long time, a simple quick check would be to take a look at the Index Properties and compare against the BigintData1 column in Profiler to gauge how may rows are remaining to be processed
or you could use a query like:
USE [database_1] GO SELECT OBJECT_NAME(id) as table_name,name AS index_name,rowcnt FROM sys.sysindexes WHERE 1=1 AND name = 'nci' GO
