@Override
@SuppressWarnings("unchecked")
protected void initializeOp(Configuration hconf) throws HiveException {
boolean isSilent = HiveConf.getBoolVar(hconf, HiveConf.ConfVars.HIVESESSIONSILENT);
console = new LogHelper(LOG, isSilent);
memoryExhaustionHandler = new MapJoinMemoryExhaustionHandler(console, conf.getHashtableMemoryUsage());
// for small tables only; so get the big table position first
posBigTableAlias = conf.getPosBigTable();