Rollback to v3.20.0 (#471)

Revert "Bump codecov/codecov-action from v1.4.1 to v1.5.0 (#466)"
This reverts commit fdc9779.

Revert "fix mistakes in documentation"
This reverts commit 4e4b5e0.

Revert "Bump pre-commit/action from v2.0.0 to v2.0.3 (#460)"
This reverts commit d027ca2.

Revert "Bump codecov/codecov-action from v1.4.0 to v1.4.1 (#461)"
This reverts commit 97cd553.

Revert "Bump codecov/codecov-action from v1.3.1 to v1.4.0 (#458)"
This reverts commit e48d67a.

Revert "Fix bug when loading few columns of a dataset with many primary indices (#446)"
This reverts commit 90ee486.

Revert "Prepare release 4.0.1"
This reverts commit b278503.

Revert "Fix tests for dask dataframe and delayed backends"
This reverts commit 5520f74.

Revert "Add end-to-end regression test"
This reverts commit 8a3e6ae.

Revert "Fix dataset corruption after updates (#445)"
This reverts commit a26e840.

Revert "Set release date for 4.0"
This reverts commit 08a8094.

Revert "Return dask scalar for store and update from ddf (#437)"
This reverts commit 494732d.

Revert "Add tests for non-default table (#440)"
This reverts commit 3807a02.

Revert "Bump codecov/codecov-action from v1.2.2 to v1.3.1 (#441)"
This reverts commit f7615ec.

Revert "Set default for dates_as_object to True (#436)"
This reverts commit 75ffdb5.

Revert "Remove inferred indices (#438)"
This reverts commit b1e2535.

Revert "fix typo: 'KTK_CUBE_UUID_SEPERATOR' -> 'KTK_CUBE_UUID_SEPARATOR' (#422)"
This reverts commit b349cee.

Revert "Remove all deprecated arguments (#434)"
This reverts commit 74f0790.

Revert "Remove multi table feature (#431)"
This reverts commit 032856a.

Author: ilia-zaitcev-by

.github/workflows/ci-pre-commit.yml

@@ -8,4 +8,4 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
-    - uses: pre-commit/[email protected].3
+    - uses: pre-commit/[email protected].0

.github/workflows/ci.yml

@@ -135,7 +135,7 @@ jobs:
         run: python setup.py sdist bdist_wheel
 
       - name: Codecov
-        uses: codecov/codecov-action@v1.5.0
+        uses: codecov/codecov-action@v1.2.2
         with:
           # NOTE: `token` is not required, because the kartothek repo is public
           file: ./coverage.xml

CHANGES.rst

@@ -2,11 +2,23 @@
 Changelog
 =========
 
+Version 5.0.0 (2021-05-xx)
+==========================
+
+This release rolls all the changes introduced with 4.x back to 3.20.0.
+
+As the incompatibility between 4.0 and 5.0 will be an issue for some customers, we encourage you to use the very stable
+kartothek 3.20.0 and not version 4.x.
+
+Please refer the Issue #471 for further information.
+
 
 Kartothek 4.0.3 (2021-06-10)
 ============================
+
 * Pin dask to not use 2021.5.1 and 2020.6.0 (#475)
 
+
 Kartothek 4.0.2 (2021-06-07)
 ============================
 

asv_bench/benchmarks/index.py

@@ -131,7 +131,9 @@ def setup(self, cardinality, num_values, partitions_to_merge):
                 unique_vals = ["{:010d}".format(n) for n in range(cardinality)]
                 array = [unique_vals[x % len(unique_vals)] for x in range(num_values)]
             self.df = pd.DataFrame({self.column: array})
-            self.mp = MetaPartition(label=self.table, data=self.df, metadata_version=4)
+            self.mp = MetaPartition(
+                label=self.table, data={"core": self.df}, metadata_version=4
+            )
             self.mp_indices = self.mp.build_indices([self.column])
             self.merge_indices.append(self.mp_indices)
 

asv_bench/benchmarks/metapartition.py

@@ -33,14 +33,15 @@ def setup(self, num_rows, dtype):
         self.mp = MetaPartition(
             label="primary_key={}/base_label".format(dtype[0]),
             metadata_version=4,
-            schema=self.schema,
+            table_meta={"table": self.schema},
         )
 
     def time_reconstruct_index(self, num_rows, dtype):
 
         self.mp._reconstruct_index_columns(
             df=self.df,
             key_indices=[("primary_key", str(dtype[1]))],
+            table="table",
             columns=None,
             categories=None,
             date_as_object=False,
@@ -50,7 +51,8 @@ def time_reconstruct_index_categorical(self, num_rows, dtype):
         self.mp._reconstruct_index_columns(
             df=self.df,
             key_indices=[("primary_key", str(dtype[1]))],
+            table="table",
             columns=None,
-            categories="primary_key",
+            categories={"table": ["primary_key"]},
             date_as_object=False,
         )

asv_bench/benchmarks/write.py

@@ -17,11 +17,12 @@
 from .config import AsvBenchmarkConfig
 
 
-def generate_mp():
+def generate_mp(dataset_metadata=None):
     return MetaPartition(
         label=uuid.uuid4().hex,
-        schema=make_meta(get_dataframe_alltypes(), origin="alltypes"),
-        file="fakefile",
+        table_meta={"table": make_meta(get_dataframe_alltypes(), origin="alltypes")},
+        files={"table": "fakefile"},
+        dataset_metadata=dataset_metadata,
     )
 
 
@@ -49,7 +50,8 @@ class TimeStoreDataset(AsvBenchmarkConfig):
 
     def setup(self, num_partitions, max_depth, num_leafs):
         self.store = get_store_from_url("hfs://{}".format(tempfile.mkdtemp()))
-        self.partitions = [generate_mp() for _ in range(num_partitions)]
+        dataset_metadata = generate_metadata(max_depth, num_leafs)
+        self.partitions = [generate_mp(dataset_metadata) for _ in range(num_partitions)]
         self.dataset_uuid = "dataset_uuid"
         self.user_dataset_metadata = {}
 
@@ -68,10 +70,8 @@ class TimePersistMetadata(AsvBenchmarkConfig):
 
     def setup(self, num_partitions):
         self.store = get_store_from_url("hfs://{}".format(tempfile.mkdtemp()))
-        self.schemas = [generate_mp().schema for _ in range(num_partitions)]
+        self.partitions = [generate_mp() for _ in range(num_partitions)]
         self.dataset_uuid = "dataset_uuid"
 
     def time_persist_common_metadata(self, num_partitions):
-        persist_common_metadata(
-            self.schemas, None, self.store, self.dataset_uuid, "name"
-        )
+        persist_common_metadata(self.partitions, None, self.store, self.dataset_uuid)

docs/conf.py

@@ -129,3 +129,8 @@
     "kartothek.serialization._generic": "kartothek.serialization",
     "kartothek.serialization._parquet": "kartothek.serialization",
 }
+
+# In particular the deprecation warning in DatasetMetadata.table_schema is
+# raising too many warning to handle sensibly using ipython directive pseudo
+# decorators. Remove this with 4.X again
+ipython_warning_is_error = False

docs/guide/examples.rst

@@ -36,7 +36,7 @@ Setup a store
 
     # Load your data
     # By default the single dataframe is stored in the 'core' table
-    df_from_store = read_table(store=store_url, dataset_uuid=dataset_uuid)
+    df_from_store = read_table(store=store_url, dataset_uuid=dataset_uuid, table="table")
     df_from_store
 
 
@@ -58,8 +58,14 @@ Write
 
     # We'll define two partitions which both have two tables
     input_list_of_partitions = [
-        pd.DataFrame({"A": range(10)}),
-        pd.DataFrame({"A": range(10, 20)}),
+        {
+            "label": "FirstPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
+        {
+            "label": "SecondPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
     ]
 
     # The pipeline will return a :class:`~kartothek.core.dataset.DatasetMetadata` object
@@ -90,10 +96,17 @@ Read
     # In case you were using the dataset created in the Write example
     for d1, d2 in zip(
         list_of_partitions,
-        [pd.DataFrame({"A": range(10)}), pd.DataFrame({"A": range(10, 20)}),],
+        [
+            # FirstPartition
+            {"FirstCategory": pd.DataFrame(), "SecondCategory": pd.DataFrame()},
+            # SecondPartition
+            {"FirstCategory": pd.DataFrame(), "SecondCategory": pd.DataFrame()},
+        ],
     ):
-        for k1, k2 in zip(d1, d2):
-            assert k1 == k2
+        for kv1, kv2 in zip(d1.items(), d2.items()):
+            k1, v1 = kv1
+            k2, v2 = kv2
+            assert k1 == k2 and all(v1 == v2)
 
 
 Iter
@@ -107,8 +120,14 @@ Write
     from kartothek.api.dataset import store_dataframes_as_dataset__iter
 
     input_list_of_partitions = [
-        pd.DataFrame({"A": range(10)}),
-        pd.DataFrame({"A": range(10, 20)}),
+        {
+            "label": "FirstPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
+        {
+            "label": "SecondPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
     ]
 
     # The pipeline will return a :class:`~kartothek.core.dataset.DatasetMetadata` object
@@ -141,10 +160,17 @@ Read
     # In case you were using the dataset created in the Write example
     for d1, d2 in zip(
         list_of_partitions,
-        [pd.DataFrame({"A": range(10)}), pd.DataFrame({"A": range(10, 20)}),],
+        [
+            # FirstPartition
+            {"FirstCategory": pd.DataFrame(), "SecondCategory": pd.DataFrame()},
+            # SecondPartition
+            {"FirstCategory": pd.DataFrame(), "SecondCategory": pd.DataFrame()},
+        ],
     ):
-        for k1, k2 in zip(d1, d2):
-            assert k1 == k2
+        for kv1, kv2 in zip(d1.items(), d2.items()):
+            k1, v1 = kv1
+            k2, v2 = kv2
+            assert k1 == k2 and all(v1 == v2)
 
 Dask
 ````
@@ -158,8 +184,14 @@ Write
     from kartothek.api.dataset import store_delayed_as_dataset
 
     input_list_of_partitions = [
-        pd.DataFrame({"A": range(10)}),
-        pd.DataFrame({"A": range(10, 20)}),
+        {
+            "label": "FirstPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
+        {
+            "label": "SecondPartition",
+            "data": [("FirstCategory", pd.DataFrame()), ("SecondCategory", pd.DataFrame())],
+        },
     ]
 
     # This will return a :class:`~dask.delayed`. The figure below

docs/guide/getting_started.rst

@@ -5,6 +5,10 @@ Getting Started
 ===============
 
 
+Kartothek manages datasets that consist of files that contain tables. It does so by offering
+a metadata definition to handle these datasets efficiently.
+
+Datasets in Kartothek are made up of one or more ``tables``, each with a unique schema.
 When working with Kartothek tables as a Python user, we will use :class:`~pandas.DataFrame`
 as the user-facing type.
 
@@ -127,25 +131,33 @@ This class holds information about the structure and schema of the dataset.
 
 .. ipython:: python
 
-    dm.table_name
+    dm.tables
     sorted(dm.partitions.keys())
-    dm.schema.remove_metadata()
+    dm.table_meta["table"].remove_metadata()  # Arrow schema
+
 
+For this guide, two attributes that are noteworthy are ``tables`` and ``partitions``:
 
-For this guide we want to take a closer look at the ``partitions`` attribute.
-``partitions`` are the physical "pieces" of data which together constitute the
-contents of a dataset. Data is written to storage on a per-partition basis. See
-the section on partitioning for further details: :ref:`partitioning_section`.
+- Each dataset has one or more ``tables``, where each table is a logical collection of data,
+  bound together by a common schema.
+- ``partitions`` are the physical "pieces" of data which together constitute the
+  contents of a dataset. Data is written to storage on a per-partition basis.
+  See the section on partitioning for further details: :ref:`partitioning_section`.
 
-The attribute ``schema`` can be accessed to see the underlying schema of the dataset.
+The attribute ``table_meta`` can be accessed to see the underlying schema of the dataset.
 See :ref:`type_system` for more information.
 
 To store multiple dataframes into a dataset, it is possible to pass a collection of
 dataframes; the exact format will depend on the I/O backend used.
 
-Kartothek assumes these dataframes are different chunks of the same table and
-will therefore be required to have the same schema. A ``ValueError`` will be
-thrown otherwise.
+Additionally, Kartothek supports several data input formats,
+it does not need to always be a plain ``pd.DataFrame``.
+See :func:`~kartothek.io_components.metapartition.parse_input_to_metapartition` for
+further details.
+
+If table names are not specified when passing an iterator of dataframes,
+Kartothek assumes these dataframes are different chunks of the same table
+and expects their schemas to be identical. A ``ValueError`` will be thrown otherwise.
 For example,
 
 .. ipython:: python
@@ -182,6 +194,39 @@ For example,
 .. note:: Read these sections for more details: :ref:`type_system`, :ref:`dataset_spec`
 
 
+When we do not explicitly define the name of the table and partition, Kartothek uses the
+default table name ``table`` and generates a UUID for the partition name.
+
+.. admonition:: A more complex example: multiple named tables
+
+    Sometimes it may be useful to write multiple dataframes with different schemas into
+    a single dataset. This can be achieved by creating a dataset with multiple tables.
+
+    In this example, we create a dataset with two tables: ``core-table`` and ``aux-table``.
+    The schemas of the tables are identical across partitions (each dictionary in the
+    ``dfs`` list argument represents a partition).
+
+    .. ipython:: python
+
+        dfs = [
+            {
+                "data": {
+                    "core-table": pd.DataFrame({"id": [22, 23], "f": [1.1, 2.4]}),
+                    "aux-table": pd.DataFrame({"id": [22], "col1": ["x"]}),
+                }
+            },
+            {
+                "data": {
+                    "core-table": pd.DataFrame({"id": [29, 31], "f": [3.2, 0.6]}),
+                    "aux-table": pd.DataFrame({"id": [31], "col1": ["y"]}),
+                }
+            },
+        ]
+
+        dm = store_dataframes_as_dataset(store_url, dataset_uuid="two-tables", dfs=dfs)
+        dm.tables
+
+
 Reading data from storage
 =========================
 
@@ -193,24 +238,24 @@ table of the dataset as a pandas DataFrame.
 
     from kartothek.api.dataset import read_table
 
-    read_table("a_unique_dataset_identifier", store_url)
+    read_table("a_unique_dataset_identifier", store_url, table="table")
 
 
 We can also read a dataframe iteratively, using
-:func:`~kartothek.io.iter.read_dataset_as_dataframes__iterator`. This will return a generator of :class:`pandas.DataFrame` where every element represents one file. For example,
+:func:`~kartothek.io.iter.read_dataset_as_dataframes__iterator`. This will return a generator
+of dictionaries (one dictionary for each `partition`), where the keys of each dictionary
+represent the `tables` of the dataset. For example,
 
 .. ipython:: python
 
     from kartothek.api.dataset import read_dataset_as_dataframes__iterator
 
-    for partition_index, df in enumerate(
-        read_dataset_as_dataframes__iterator(
-            dataset_uuid="a_unique_dataset_identifier", store=store_url
-        )
+    for partition_index, df_dict in enumerate(
+        read_dataset_as_dataframes__iterator(dataset_uuid="two-tables", store=store_url)
     ):
-        # Note: There is no guarantee on the ordering
         print(f"Partition #{partition_index}")
-        print(f"Data: \n{df}")
+        for table_name, table_df in df_dict.items():
+            print(f"Table: {table_name}. Data: \n{table_df}")
 
 Respectively, the ``dask.delayed`` back-end provides the function
 :func:`~kartothek.io.dask.delayed.read_dataset_as_delayed`, which has a very similar
@@ -230,7 +275,8 @@ function but returns a collection of ``dask.delayed`` objects.
 
     .. ipython:: python
 
-        read_table("a_unique_dataset_identifier", store_url, predicates=[[("A", "<", 2.5)]])
+        # Read only values table `core-table` where `f` < 2.5
+        read_table("two-tables", store_url, table="core-table", predicates=[[("f", "<", 2.5)]])
 
 .. _storefact: https://github.com/blue-yonder/storefact
 .. _dask: https://docs.dask.org/en/latest/