public ShowCQResp showCQ() {
    lock.readLock().lock();
    try {
      return new ShowCQResp(
          new TSStatus(TSStatusCode.SUCCESS_STATUS.getStatusCode()),
          cqMap.values().stream().map(CQEntry::new).collect(Collectors.toList()));
    } finally {
      lock.readLock().unlock();
    }
  }
Drop the CQ whose ID is same as <tt>cqId</tt> in plan.

@return SUCCESS_STATUS if there is CQ whose ID and md5 is same as <tt>cqId</tt> in plan,
    otherwise NO_SUCH_CQ.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/persistence/cq/CQInfo.java