Add support for Dremio as a new source (#8939)

* Added spec for Dremio

* Installation instructions for Dremio

* added dependency for dremio

* Update dremio.py

* ASF header, dttm, set min version in setup.py

* Update installation.rst

* Update installation.rst

* fix tox 'Title underline too short.'

* change URI example

Co-authored-by: Naren <41924335+naren-dremio@users.noreply.github.com>

docs/index.rst

@@ -109,6 +109,7 @@ The following RDBMS are currently supported:
 - `Apache Spark SQL <https://spark.apache.org/sql/>`_
 - `BigQuery <https://cloud.google.com/bigquery/>`_
 - `ClickHouse <https://clickhouse.yandex/>`_
+- `Dremio <https://dremio.com/>`_
 - `Elasticsearch <https://www.elastic.co/products/elasticsearch/>`_
 - `Exasol <https://www.exasol.com/>`_
 - `Google Sheets <https://www.google.com/sheets/about/>`_

docs/installation.rst

@@ -372,6 +372,8 @@ Here's a list of some of the recommended packages.
 +------------------+---------------------------------------+-------------------------------------------------+
 | ClickHouse       | ``pip install sqlalchemy-clickhouse`` |                                                 |
 +------------------+---------------------------------------+-------------------------------------------------+
+| Dremio           | ``pip install sqlalchemy_dremio``     | ``dremio://user:pwd@host:31010/``               |
++------------------+---------------------------------------+-------------------------------------------------+
 | Elasticsearch    | ``pip install elasticsearch-dbapi``   | ``elasticsearch+http://``                       |
 +------------------+---------------------------------------+-------------------------------------------------+
 | Exasol           | ``pip install sqlalchemy-exasol``     | ``exa+pyodbc://``                               |
@@ -724,6 +726,15 @@ Druid
 Note that you can run the ``superset refresh_druid`` command to refresh the
 metadata from your Druid cluster(s)
 
+Dremio
+------
+
+Install the following dependencies to connect to Dremio:
+
+* Dremio SQLAlchemy: ``pip install sqlalchemy_dremio``
+* Dremio's ODBC driver: https://www.dremio.com/drivers/
+
+Example SQLAlchemy URI: ``dremio://dremio:dremio123@localhost:31010/dremio``
 
 Presto
 ------

setup.py

@@ -118,6 +118,7 @@ setup(
         "elasticsearch": ["elasticsearch-dbapi>=0.1.0, <0.2.0"],
         "druid": ["pydruid==0.5.7", "requests==2.22.0"],
         "hana": ["hdbcli==2.4.162", "sqlalchemy_hana==0.4.0"],
+        "dremio": ["sqlalchemy_dremio>=0.5.0dev0"],
     },
     python_requires="~=3.6",
     author="Apache Software Foundation",

superset/db_engine_specs/dremio.py

@@ -0,0 +1,38 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+from superset.db_engine_specs.base import BaseEngineSpec
+
+
+class DremioBaseEngineSpec(BaseEngineSpec):
+
+    engine = "dremio"
+
+    _time_grain_functions = {
+        None: "{col}",
+        "PT1S": "DATE_TRUNC('second', {col})",
+        "PT1M": "DATE_TRUNC('minute', {col})",
+        "PT1H": "DATE_TRUNC('hour', {col})",
+        "P1D": "DATE_TRUNC('day', {col})",
+        "P1W": "DATE_TRUNC('week', {col})",
+        "P1M": "DATE_TRUNC('month', {col})",
+        "P0.25Y": "DATE_TRUNC('quarter', {col})",
+        "P1Y": "DATE_TRUNC('year', {col})",
+    }
+
+    @classmethod
+    def epoch_to_dttm(cls) -> str:
+        return "TO_DATE({col})"