private void validateTableType(Table tbl) {
    // If the table has property EXTERNAL set, update table type
    // accordingly
    String tableType = tbl.getTableType();
    boolean isExternal = Boolean.parseBoolean(tbl.getParameters().get("EXTERNAL"));
    if (TableType.MANAGED_TABLE.toString().equals(tableType)) {
      if (isExternal) {
        tableType = TableType.EXTERNAL_TABLE.toString();
      }
    }
    if (TableType.EXTERNAL_TABLE.toString().equals(tableType)) {
      if (!isExternal) {
        tableType = TableType.MANAGED_TABLE.toString();
      }
    }
    tbl.setTableType(tableType);
  }
This starts a background thread, which initially populates the SharedCache and later
periodically gets updates from the metastore db

@param conf
@param runOnlyOnce
@param shouldRunPrewarm
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/cache/CachedStore.java