public static PartitionSpec spec(Schema schema, List<FieldSchema> fieldSchemas) {
    PartitionSpec.Builder builder = PartitionSpec.builderFor(schema);
    fieldSchemas.forEach(fieldSchema -> builder.identity(fieldSchema.getName().toLowerCase()));
    return builder.build();
  }
Converts the Hive partition columns to Iceberg identity partition specification.
@param schema The Iceberg schema
@param fieldSchemas The partition column specification
@return The Iceberg partition specification
iceberg/iceberg-catalog/src/main/java/org/apache/iceberg/hive/HiveSchemaUtil.java