Repository: modin-project/modin
Pull request: DOCS-#4176: Update OmniSci usage section
Signed-off-by: izamyati <igor.zamyatin@intel.com>

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## What do these changes do?

<!-- Please give a short brief about these changes. -->

Give some details about using engine settings in case of Omnisci

- [x] commit message follows format outlined [here](https://modin.readthedocs.io/en/latest/development/contributing.html#commit-message-formatting)
- [x] passes `flake8 modin/ asv_bench/benchmarks scripts/doc_checker.py`
- [x] passes `black --check modin/ asv_bench/benchmarks scripts/doc_checker.py`
- [x] signed commit with `git commit -s` <!-- you can amend your commit with a signature via `git commit -amend -s` -->
- [x] Resolves #4176 <!-- issue must be created for each patch -->
- [x] tests added and passing
- [x] module layout described at `docs/development/architecture.rst` is up-to-date <!-- if you have added, renamed or removed files or directories please update the documentation accordingly -->
- [x] added (Issue Number: PR title (PR Number)) and github username to release notes for next major release <!-- e.g. DOCS-#4077: Add release notes template to docs folder (#4078) -->


Problem statement:
Update OmniSci usage section
We should mention that users have to set `IsExperimental` config or `MODIN_EXPERIMENTAL` env var in the case of setting `StorageFormat` to `omnisci` and `Engine` to `native`. Otherwise, the following error is arisen.

```python
FactoryNotFoundError: Omnisci on Native is only accessible through the experimental API.
Run `import modin.experimental.pandas as pd` to use Omnisci on Native.
```

Hints from issue discussion:

Commit message: release notes update

Signed-off-by: izamyati <igor.zamyatin@intel.com>

Patch to review:
diff --git a/docs/development/using_omnisci.rst b/docs/development/using_omnisci.rst
index 45cb8b1f31d..9ef1e8f2cc9 100644
--- a/docs/development/using_omnisci.rst
+++ b/docs/development/using_omnisci.rst
@@ -18,8 +18,15 @@ or use it in your code:
    import modin.config as cfg
    cfg.StorageFormat.put('omnisci')
 
-Since OmniSci is run through its native engine Modin itself sets ``MODIN_ENGINE=Native``
-and you might not specify it explicitly.
+Since OmniSci is run through its native engine, Modin automatically sets ``MODIN_ENGINE=Native`` and you might not specify it explicitly.
+If for some reasons ``Native`` engine is explicitly set using modin.config or environment variable, make sure you also tell modin that
+``Experimental`` mode is turned on (``export MODIN_EXPERIMENTAL=true`` or ``cfg.IsExperimental.put(True)``) otherwise following error occurs:
+
+.. code-block:: bash
+
+   FactoryNotFoundError: Omnisci on Native is only accessible through the experimental API.
+   Run `import modin.experimental.pandas as pd` to use Omnisci on Native.
+
 
 .. note::
    If you encounter ``LLVM ERROR: inconsistency in registered CommandLine options`` error when using OmniSci,
diff --git a/docs/release_notes/release_notes-0.14.0.rst b/docs/release_notes/release_notes-0.14.0.rst
index b981a1645f9..ce794a624a0 100644
--- a/docs/release_notes/release_notes-0.14.0.rst
+++ b/docs/release_notes/release_notes-0.14.0.rst
@@ -35,6 +35,7 @@ Key Features and Updates
   * DOCS-#4151: Add info in troubleshooting page related to Dask engine usage (#4152)
   * DOCS-#4172: Refresh Intel Distribution of Modin paragraph (#4175)
   * DOCS-#4173: Mention strict channel priority in conda install section (#4178)
+  * DOCS-#4176: Update OmniSci usage section (#4192)
 * Dependencies
   * FIX-#4113, FIX-#4116, FIX-#4115: Apply new `black` formatting, fix pydocstyle check and readthedocs build (#4114)
   * TEST-#3227: Use codecov github action instead of bash form in GA workflows (#3226)


Code review comments:
diff_hunk: @@ -18,8 +18,15 @@ or use it in your code:
    import modin.config as cfg
    cfg.StorageFormat.put('omnisci')
 
-Since OmniSci is run through its native engine Modin itself sets ``MODIN_ENGINE=Native``
-and you might not specify it explicitly.
+Since OmniSci is run through its native engine, Modin automatically sets ``MODIN_ENGINE=Native`` and you might not specify it explicitly.
+If for some reasons ``Native`` engine is explicitly set using modin.config or environment variable, make sure you also tell modin that
+``Experimental`` mode is turned on (``export MODIN_EXPERIMENTAL=true`` or ``cfg.IsExperimental.put(True)``) otherwise following error occurs:
path: docs/development/using_omnisci.rst
text: @user1:
```suggestion
``Experimental`` mode is turned on (``export MODIN_EXPERIMENTAL=true`` or 
``cfg.IsExperimental.put(True)``) otherwise the following error occurs:
```