I am looking for feedback/comments on teiiddes-196 - "Change default for UDF property
*deterministic* from false to true to improve usability". This would change the
default value in the Designer for the 'deterministic' property of new User Defined
Functions from 'false' to 'true'. Because the default is 'false'
and most UDFs are deterministic, it seems to get set incorrectly, probably because most
users don't think to set it explicitly and leave it at the default setting. Setting a
UDF to non-deterministic when it should be deterministic will cause the planner to miss
opportunities to optimize.
On the other side, specifying a UDF as deterministic when it is non-deterministic could
lead to unreliable results. I think this is not as likely to happen because a person
developing a non-deterministic UDF will be very aware of that fact.
There is a bit more detail in the Jira.