@Override
  public boolean namespaceExists(String[] namespace) {
    return unifiedCatalog.databaseExists(namespaceToDatabase(namespace));
  }
Unified catalog implement for spark engine.
amoro-format-mixed/amoro-mixed-spark/amoro-mixed-spark-3-common/src/main/java/org/apache/amoro/spark/SparkUnifiedCatalogBase.java