planStr.addDetail("out schema: ").appendDetail(getOutSchema().toString());
planStr.addDetail("in schema: ").appendDetail(getInSchema().toString());
if (inputPaths != null) {
planStr.addExplan("num of filtered paths: ").appendExplain(""+ inputPaths.length);
int i = 0;
for (Path path : inputPaths) {
planStr.addDetail((i++) + ": ").appendDetail(path.toString());
}
}