feat: Switch from Feature to Field

[felixwang9817]

What this PR does / why we need it: This PR switches FeatureViews to declare features using the Field class and deprecates Feature. It also deprecates positional arguments for on demand feature views, and deprecates the features parameter for feature views and on demand feature views in favor of the schema parameter.

Which issue(s) this PR fixes:

Fixes #

[codecov-commenter]

Codecov Report

Merging #2514 (9bd3761) into master (46b9044) will increase coverage by 0.80%.
The diff coverage is 94.89%.

@@            Coverage Diff             @@
##           master    #2514      +/-   ##
==========================================
+ Coverage   84.43%   85.23%   +0.80%     
==========================================
  Files         134      133       -1     
  Lines       11249    11232      -17     
==========================================
+ Hits         9498     9574      +76     
+ Misses       1751     1658      -93     

Flag	Coverage Δ
integrationtests	74.09% <91.83%> (-0.11%)	⬇️
unittests	59.68% <62.24%> (+0.49%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...n/tests/integration/registration/test_inference.py	100.00% <ø> (ø)
...tegration/feature_repos/universal/feature_views.py	83.07% <80.00%> (-0.80%)	⬇️
sdk/python/feast/feature_view_projection.py	96.42% <85.71%> (-3.58%)	⬇️
sdk/python/feast/on_demand_feature_view.py	95.28% <92.10%> (+0.16%)	⬆️
sdk/python/feast/__init__.py	91.66% <100.00%> (+0.75%)	⬆️
sdk/python/feast/base_feature_view.py	80.00% <100.00%> (+0.68%)	⬆️
sdk/python/feast/feature_view.py	85.89% <100.00%> (+0.76%)	⬆️
sdk/python/feast/inference.py	85.91% <100.00%> (+0.62%)	⬆️
sdk/python/feast/infra/provider.py	89.51% <100.00%> (ø)
sdk/python/feast/request_feature_view.py	67.56% <100.00%> (ø)
... and 21 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 46b9044...9bd3761. Read the comment docs.

[achals]

looks good overall

[achals]

should we import the types from a different namespace? To keep things better organized? I'm okay with things the way they are for now but just floating the idea.

[felixwang9817]

ah that's a good (non-blocking) idea - I think from feast.typing import Float32, Int64 etc. would be much cleaner

[achals]

nit, list of fields? fine with list of features

[felixwang9817]

prefer list of features since features here actually refers to features; e.g. I would consider schema a list of fields since it contains not just features but also join keys, but features I consider a list of features

[achals]

Is there a reason this was removed?

[felixwang9817]

I think it's a bit unnecessary since this initialization happens only internally; the check should still happen so I'm going to switch to an assert (since we expect it to always pass)

[achals]

Is the intention that schema should always include the timestamps and entities? Or that they can be optionally included, and we'll try to infer and split them if they are in the schema?

[felixwang9817]

the latter - we should continue to support inference

specifically, our current inference logic should be fine - timestamp columns are inferred based on the underlying data sources, entity columns are inferred based on entity join keys, and feature columns are the remaining

[achals]

/lgtm

[feast-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: achals, felixwang9817

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [achals,felixwang9817]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment