@Override public List<String> getTables(String catName, String dbName, String pattern, TableType tableType, int limit)
      throws MetaException {
    return rawStore.getTables(catName, dbName, pattern, tableType, limit);
  }
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