public void close() throws Exception {
    if (kvTable != null) {
      kvTable.close();
    }
    if (executor != null) {
      executor.shutdownNow();
    }
  }
Check whether it is time to periodically load data to kvTable. Support to use {@link
Expression} filters to filter the data.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/lookup/BasicLookupFunction.java