public static void warmup() {
    JaninoRelMetadataProvider.DEFAULT.register(HIVE_REL_NODE_CLASSES);
    HiveDefaultRelMetadataProvider.initializeMetadataProviderClass(HIVE_REL_NODE_CLASSES);
    HiveTezModelRelMetadataProvider.DEFAULT.register(HIVE_REL_NODE_CLASSES);
    HiveMaterializationRelMetadataProvider.DEFAULT.register(HIVE_REL_NODE_CLASSES);
    HiveRelFieldTrimmer.initializeFieldTrimmerClass(HIVE_REL_NODE_CLASSES);
  }
This method can be called at startup time to pre-register all the
additional Hive classes (compared to Calcite core classes) that may
be visited during the planning phase in the metadata providers
and the field trimmer.
ql/src/java/org/apache/hadoop/hive/ql/parse/CalcitePlanner.java