Why are the performances of these 2 queries so different?

Question

I have a stored proc that searches for products (250,000 rows) using a full text index.

The stored proc takes a parameter that is the full text search condition. This pa

Answer 1

OR can crush performance, so do it this way:

DECLARE @Filter VARCHAR(100)
SET @Filter = 'FORMSOF(INFLECTIONAL, robe)'

IF @Filter IS NOT NULL
BEGIN
    SELECT TOP 100 ID FROM dbo.Products
    WHERE CONTAINS(Name, @Filter)
END
ELSE
BEGIN
    SELECT TOP 100 ID FROM dbo.Products
END

Look at this article: Dynamic Search Conditions in T-SQL by Erland Sommarskog and this question: SQL Server 2008 - Conditional Query.