private void seekInRightStream(Object firstLeftKey) throws IOException{
rightLoader = (LoadFunc)PigContext.instantiateFuncFromSpec(rightLoaderFuncSpec);
// check if hadoop distributed cache is used
if (indexFile != null && rightLoader instanceof DefaultIndexableLoader) {
DefaultIndexableLoader loader = (DefaultIndexableLoader)rightLoader;
loader.setIndexFile(indexFile);
}
// Pass signature of the loader to rightLoader
// make a copy of the conf to use in calls to rightLoader.
rightLoader.setUDFContextSignature(signature);