scalar-setting-volatility-java.md

The following example demonstrates setting the Add2IntsFactory's vol field to IMMUTABLE to tell Vertica it can cache the arguments and return value.

public class Add2IntsFactory extends ScalarFunctionFactory {

    @Override
    public void getPrototype(ServerInterface srvInterface, ColumnTypes argTypes, ColumnTypes returnType){
        argTypes.addInt();
        argTypes.addInt();
        returnType.addInt();
    }

    @Override
    public ScalarFunction createScalarFunction(ServerInterface srvInterface){
        return new Add2Ints();
    }

    // Class constructor
    public Add2IntsFactory() {
        // Tell Vertica that the same set of arguments will always result in the
        // same return value.
        vol = volatility.IMMUTABLE;
    }
}