Set<Map.Entry<JoinOperator, QBJoinTree>> joinCtx = pGraphContext.getJoinContext().entrySet();
Iterator<Map.Entry<JoinOperator, QBJoinTree>> joinCtxIter = joinCtx.iterator();
while (joinCtxIter.hasNext()) {
Map.Entry<JoinOperator, QBJoinTree> joinEntry = joinCtxIter.next();
JoinOperator joinOp = joinEntry.getKey();
QBJoinTree qbJoin = joinEntry.getValue();
int mapJoinPos = mapSideJoin(joinOp, qbJoin);
if (mapJoinPos >= 0) {
MapJoinOperator mapJoinOp = generateMapJoinOperator(pactx, joinOp, qbJoin, mapJoinPos);
listMapJoinOps.add(mapJoinOp);
mapJoinMap.put(mapJoinOp, qbJoin);