@Override public void alterCatalog(String catName, Catalog cat) throws MetaException, InvalidOperationException {
    rawStore.alterCatalog(catName, cat);
    // in case of event based cache update, cache will not be updated for catalog.
    if (!canUseEvents) {
      sharedCache.alterCatalogInCache(StringUtils.normalizeIdentifier(catName), cat);
    }
  }
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