[GSK-2346] Avoid copying whole dataset when doing slicing (#1673)

Avoid copying whole dataset when doing slicing

Co-authored-by: Kevin Messiaen <[email protected]>

Author: Hartorn

giskard/datasets/base/__init__.py

@@ -1,3 +1,5 @@
+from typing import Dict, Hashable, List, Optional, Union
+
 import inspect
 import logging
 import posixpath
@@ -12,14 +14,13 @@
 import yaml
 from mlflow import MlflowClient
 from pandas.api.types import is_list_like, is_numeric_dtype
-from typing import Dict, Hashable, List, Optional, Union
 from xxhash import xxh3_128_hexdigest
 from zstandard import ZstdDecompressor
 
 from giskard.client.giskard_client import GiskardClient
 from giskard.client.io_utils import compress, save_df
 from giskard.client.python_utils import warning
-from giskard.core.core import DatasetMeta, SupportedColumnTypes, NOT_GIVEN, NotGivenOr
+from giskard.core.core import NOT_GIVEN, DatasetMeta, NotGivenOr, SupportedColumnTypes
 from giskard.core.errors import GiskardImportError
 from giskard.core.validation import configured_validate_arguments
 from giskard.ml_worker.testing.registry.slicing_function import SlicingFunction, SlicingFunctionType
@@ -28,8 +29,9 @@
     TransformationFunctionType,
 )
 from giskard.settings import settings
-from ..metadata.indexing import ColumnMetadataMixin
+
 from ...ml_worker.utils.file_utils import get_file_name
+from ..metadata.indexing import ColumnMetadataMixin
 
 try:
     import wandb  # noqa
@@ -77,8 +79,11 @@ def add_step(self, processor: Union[SlicingFunction, TransformationFunction]):
             self.pipeline.append(processor)
         return self
 
-    def apply(self, dataset: "Dataset", apply_only_last=False, get_mask: bool = False):
-        ds = dataset.copy()
+    def apply(self, dataset: "Dataset", apply_only_last=False, get_mask: bool = False, copy: bool = True):
+        if copy:
+            ds = dataset.copy()
+        else:
+            ds = dataset
         is_slicing_only = True
 
         while len(self.pipeline):
@@ -330,7 +335,9 @@ def slice(
                 **{key: value for key, value in slicing_function.params.items() if key != "column_name"},
             )
 
-        return self.data_processor.add_step(slicing_function).apply(self, apply_only_last=True, get_mask=get_mask)
+        return self.data_processor.add_step(slicing_function).apply(
+            self, apply_only_last=True, get_mask=get_mask, copy=False
+        )
 
     @configured_validate_arguments
     def transform(