I have a Full-text Search query as mentioned below.

SELECT * FROM CONTAINSTABLE(TABLE_NAME, COL_Name,
N'ISABOUT(FORMSOF(INFLECTIONAL, TEXT_HERE))') ORDER BY Rank DESC

The table, TABLE_NAME contains around 800 rows and the column COL_Name is
data type of nvarchar(255).

The above query taking around 60 seconds when i execute it very first time.
And in next sub-sequent executions it is taking less than 1 second.

If i execute the same query after 30 minutes (without performing any thing),
in the first time it is taking again 60 seconds.

What whould be the problem here?

Thanks,
Naveen