ALTER TRIGGER TR_UpdateTable_SetGlobalNumber ON dbo.Updates
INSTEAD OF INSERT
AS 

BEGIN

   DECLARE insertedItems CURSOR FAST_FORWARD FOR 
      SELECT TableId,ColumnsChanged,RowGuidValue,Operation,UpdateId,ShadowId
      FROM inserted

      DECLARE @tableId uniqueidentifier
      DECLARE @columnsChanged varbinary(15)
      DECLARE @operation tinyint
      DECLARE @idValue uniqueidentifier
      DECLARE @updateId uniqueidentifier
      DECLARE @numInInserted bigint
      DECLARE @offset bigint
      DECLARE @nextNum bigint
      DECLARE @nextIncrement bigint
      DECLARE @globalUpdateNumber bigint
      DECLARE @shadowId uniqueidentifier
      DECLARE @doIncrement tinyint

      OPEN insertedItems

      SET @numInInserted = @@CURSOR_ROWS

      -- within this transaction I dont want the GlobalUpdateNumber
      -- table to be available to any other calls
      
      BEGIN TRANSACTION

      SELECT @globalUpdateNumber=UpdateNumber,@nextIncrement=UpdateIncrement
      FROM GlobalUpdateNumber

      IF ( 9223372036854775800 - @globalUpdateNumber < @numInInserted )
      BEGIN
         SET @doIncrement = 1
         SET @offset = @numInInserted - (9223372036854775800 - @globalUpdateNumber)

         UPDATE GlobalUpdateNumber SET UpdateNumber = @offset, UpdateIncrement=UpdateIncrement+1

         SET @nextNum = 9223372036854775800-@numInInserted+@offset
      END
      ELSE
      BEGIN
         SET @doIncrement = 0
         UPDATE GlobalUpdateNumber SET UpdateNumber = @globalUpdateNumber + @numInInserted

         SET @nextNum = @globalUpdateNumber
      END

      COMMIT
      

      FETCH NEXT FROM insertedItems INTO @tableId,@columnsChanged,@idValue,@operation,@updateId,@shadowId

      WHILE @@FETCH_STATUS = 0
      BEGIN
           
         INSERT INTO Updates (TableId,ColumnsChanged,RowGuidValue,Operation,GlobalChangeNumber,GCNIncrement,UpdateId,ShadowId)
         VALUES (@tableId,@columnsChanged,@idValue,@operation,@nextNum,@nextIncrement,@updateId,@shadowId) 

         IF ( @doIncrement = 1 AND @nextNum > 9223372036854775800 )
         BEGIN
            SET @nextNum = 0
            SET @nextIncrement = @nextIncrement + 1
         END
         ELSE
            SET @nextNum = @nextNum + 1

         FETCH NEXT FROM insertedItems INTO @tableId,@columnsChanged,@idValue,@operation,@updateId,@shadowId
   
      END

   CLOSE insertedItems
   DEALLOCATE insertedItems
END