/**
* Tests whether we can support the usage of dynamic parameters in a given SargExpr.
*
* @param sargExpr expression to test
* @return true if supported
*/
private boolean testDynamicParamSupport(SargExpr sargExpr) {
// NOTE jvs 18-Mar-2006: we don't currently support boolean operators
// over predicates on dynamic parameters. The reason is that we
// evaluate sarg expressions at prepare time rather than at execution
// time. To support them, we would need a way to defer evaluation
// until execution time (Broadbase used to do that).
Set<RexDynamicParam> dynamicParams = new HashSet<RexDynamicParam>();
sargExpr.collectDynamicParams(dynamicParams);
if (dynamicParams.isEmpty()) {
// no dynamic params, no problem
return true;
}
if (sargExpr instanceof SargIntervalExpr) {
// We can support a single point or ray, which is the
// most that would have been generated by the time this is
// called. Should probably assert that.
return true;
}
// Anything else is unsupported.
return false;
}
// implement SargExpr
public void collectDynamicParams(Set<RexDynamicParam> dynamicParams) {
for (SargExpr child : children) {
child.collectDynamicParams(dynamicParams);
}
}