Fix dask usage in tutorial docs

docs/source/tutorials/mimiciv.ipynb

@@ -265,7 +265,7 @@
    "id": "9550ba62-c128-4259-a075-0cbd9c70b662",
    "metadata": {},
    "source": [
-    "## Example 7. Get all female patient encounters from year 2015, and return as dask dataframe (lazy evaluation) with 4 partitions (batches) aggregated based on `subject_id`."
+    "## Example 7. Get all female patient encounters from year 2015, and return batches partitioned and indexed on `subject_id`."
    ]
   },
   {
@@ -286,13 +286,12 @@
     ")\n",
     "patient_admissions = patient_admissions.ops(ops)\n",
     "patient_admissions = patient_admissions.run(\n",
-    "    backend=\"dask\",\n",
     "    index_col=\"subject_id\",\n",
-    "    n_partitions=4,\n",
+    "    batch_mode=True,\n",
+    "    batch_size=1000,\n",
     ")\n",
-    "print(f\"{len(patient_admissions)} rows extracted!\")\n",
-    "print(f\"Return type: {type(patient_admissions)}\")\n",
-    "print(f\"Number of partitions: {patient_admissions.npartitions}\")"
+    "patient_admissions_df = next(patient_admissions)\n",
+    "print(f\"{len(patient_admissions_df)} rows extracted!\")"
    ]
   },
   {