[teiid-dev] Looking for comments on teiiddes-196 - Change default for UDF property *deterministic* from false to true...

Gerard Helbling ghelblin at redhat.com
Fri May 29 11:21:12 EDT 2009


Hello,

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.  

Jerry



More information about the teiid-dev mailing list