SET PARSEONLY ON Examines the syntax of each Transact-SQL statement and returns any error messages without compiling or executing the statement.
SET PARSEONLY { ON | OFF }
When SET PARSEONLY is ON, SQL Server only parses the statement. When SET PARSEONLY is OFF, SQL Server compiles and executes the statement.
The setting of SET PARSEONLY is set at parse time and not at execute or run time.
Do not use PARSEONLY in a stored procedure or a trigger. SET PARSEONLY returns offsets if the OFFSETS option is ON and no errors occur.
Here is the will do some test against it. What do you think about its execution?
set parseonly on set parseonly off
Though we reset the PARSEONLY preference, it will validate the statement but never will execute.