Class ConventionTraitDef

java.lang.Object
org.apache.calcite.plan.RelTraitDef<Convention>
org.apache.calcite.plan.ConventionTraitDef

public class ConventionTraitDef extends RelTraitDef<Convention>
Definition of the convention trait. A new set of conversion information is created for each planner that registers at least one ConverterRule instance.

Conversion data is held in a LoadingCache with weak keys so that the JVM's garbage collector may reclaim the conversion data after the planner itself has been garbage collected. The conversion information consists of a graph of conversions (from one calling convention to another) and a map of graph arcs to ConverterRules.