The introduction of the Expression.empty_aggregate_value interface allows the compilation stage to enable the EmptyResultSet optimization if all the aggregates expressions implement it. This also removes unnecessary RegrCount/Count.convert_value() methods. Disabling the empty result set aggregation optimization when it wasn't appropriate prevented None returned for a Count aggregation value. Thanks Nick Pope for the review.
The documentation in this tree is in plain text files and can be viewed using any text file viewer.
It uses ReST (reStructuredText), and the Sphinx documentation system. This allows it to be built into other forms for easier viewing and browsing.
To create an HTML version of the docs:
- Install Sphinx (using
python -m pip install Sphinx
or some other method). - In this docs/ directory, type
make html
(ormake.bat html
on Windows) at a shell prompt.
The documentation in _build/html/index.html
can then be
viewed in a web browser.