The Delay Validation property can
be set on a Data Flow task, but not on individual data flow components. We can
achieve a similar effect by setting the ValidateExternalMetadata property of
individual data flow components (i.e. OLE DB Source component) to False. However, when the value of this property is
False, the component is not aware of changes to the metadata of external data
sources.
We can see this property on the
Data Flow pan

By default, the ValidateExternalMetadata
property is set to true, so SSIS validates the external metadata whenever we
open the package, add a component, or run the package. If we override this
behavior by setting the property to False, SSIS will not validate the data
source until it runs that component.
When we set it false in this case
it will validate the connection during the execution.
Let’s see the demo
I am taking Data flow task
Now I am taking OLEDB source as
source. And creating the connection
See in this I am taking Data access mode as “SQL Command” and here I
am not writing any sql statement.
Clicking ok.
It showing the error.
Now I am setting the ValidateExternalMetadata to false.
Error disappeared.
It means it will validate during the execution.



