val COMET_NATIVE_SCAN_IMPL: ConfigEntry[String] = conf("spark.comet.scan.impl")
    .doc(
      s"The implementation of Comet Native Scan to use. Available modes are '$SCAN_NATIVE_COMET'," +
        s"'$SCAN_NATIVE_DATAFUSION', and '$SCAN_NATIVE_ICEBERG_COMPAT'. " +
        s"'$SCAN_NATIVE_COMET' is for the original Comet native scan which uses a jvm based " +
        "parquet file reader and native column decoding. Supports simple types only " +
        s"'$SCAN_NATIVE_DATAFUSION' is a fully native implementation of scan based on DataFusion" +
        s"'$SCAN_NATIVE_ICEBERG_COMPAT' is a native implementation that exposes apis to read " +
        "parquet columns natively.")
    .internal()
    .stringConf
    .transform(_.toLowerCase(Locale.ROOT))
    .checkValues(Set(SCAN_NATIVE_COMET, SCAN_NATIVE_DATAFUSION, SCAN_NATIVE_ICEBERG_COMPAT))
    .createWithDefault(sys.env
      .getOrElse("COMET_PARQUET_SCAN_IMPL", SCAN_NATIVE_COMET)
      .toLowerCase(Locale.ROOT))