public void setTTL(Map<String, Long> databaseTTLMap) throws IllegalPathException {
    lock.writeLock().lock();
    try {
      for (Map.Entry<String, Long> entry : databaseTTLMap.entrySet()) {
        String[] nodesWithWildcard =
            PathUtils.splitPathToDetachedNodes(
                entry
                    .getKey()
                    .concat(
                        IoTDBConstant.PATH_SEPARATOR + IoTDBConstant.MULTI_LEVEL_PATH_WILDCARD));
        ttlCache.setTTL(nodesWithWildcard, entry.getValue());
      }
    } finally {
      lock.writeLock().unlock();
    }
  }
Only used for upgrading from database level ttl to device level ttl.
iotdb-core/confignode/src/main/java/org/apache/iotdb/confignode/persistence/TTLInfo.java