@Override public boolean alterDatabase(String catName, String dbName, Database db)
      throws NoSuchObjectException, MetaException {
    boolean succ = rawStore.alterDatabase(catName, dbName, db);
    if (succ && !canUseEvents) {
      // in case of event based cache update, cache will be updated during commit.
      sharedCache
          .alterDatabaseInCache(StringUtils.normalizeIdentifier(catName), StringUtils.normalizeIdentifier(dbName), db);
    }
    return succ;
  }
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