public String getHiveSchemaPostfix() {
    switch (dbType) {
    case SQLSERVER:
      return "mssql";
    case DERBY:
    case MYSQL:
    case POSTGRES:
    case ORACLE:
    case CUSTOM:
      return dbType.name().toLowerCase();
    case UNDEFINED:
    default:
      return null;
    }
  }
Whether the RDBMS has a bug in join and filter operation order described in DERBY-6358.
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/DatabaseProduct.java