Try the Parsename function. Not what is was made for, but works quite well for what you need and is much faster that CharIndex and Len.

Duration for CHARINDEX = 00:00:00:933

Duration for Len = 00:00:00:607

Duration for PARSENAME = 00:00:00:127

SET NOCOUNT ON;

IF object_id('tempdb..#testEnvironment') IS NOT NULL

BEGIN

DROP TABLE #testEnvironment;

END;

--1,000,000 Random rows of data

SELECT IDENTITY(INT,1,1) AS ID, CAST(LEFT(yourData, LEN(yourData) - 1) AS varchar(50)) AS yourData

INTO #testEnvironment

FROM (SELECT TOP 1000000

REPLICATE(

REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(

REPLACE(NEWID(),'-','')

,'0',''),'9',''),'8',''),'7',''),'6',''),'5',''),'4',''),'3',''),'2',''),'1','') + '.',

(ABS(CHECKSUM(NEWID())) % 2) + 2)

FROM master.dbo.syscolumns sc1, master.dbo.syscolumns sc2, master.dbo.syscolumns sc3

)a(yourData);

--select * from #testEnvironment where PARSENAME(yourData,3) is null --00:00:48:00

DECLARE @HOLDER INT, @Duration CHAR(12), @StartTime DATETIME;

SELECT @StartTime = GETDATE();

SELECT @HOLDER = ID

FROM #testEnvironment

WHERE CHARINDEX('.', yourData, CHARINDEX('.', yourData) + 1) = 0;

SELECT @Duration = CONVERT(CHAR(12),GETDATE()-@StartTime,114);

RAISERROR('Duration for CHARINDEX = %s',0,1,@Duration) WITH NOWAIT;

SELECT @StartTime = SYSDATETIME();

SELECT @HOLDER = ID

FROM #testEnvironment

WHERE LEN(CAST(yourData AS NVARCHAR(MAX)))-1 = LEN(REPLACE(CAST(yourData AS NVARCHAR(MAX)) COLLATE Latin1_General_BIN2,'.',''));

SELECT @Duration = CONVERT(CHAR(12),GETDATE()-@StartTime,114);

RAISERROR('Duration for Len = %s',0,1,@Duration) WITH NOWAIT;

SELECT @StartTime = SYSDATETIME();

select @HOLDER = ID from #testEnvironment where PARSENAME(yourData,3) is null

SELECT @Duration = CONVERT(CHAR(12),GETDATE()-@StartTime,114);

RAISERROR('Duration for PARSENAME = %s',0,1,@Duration) WITH NOWAIT;