Returns the mean of the independent_variable_expression for all non-null data pairs of the dependent and independent variable arguments.
For the REGR_AVGX window function that performs a group, cumulative, or moving computation, see Window Aggregate Functions.
Computation
When there are fewer than two non-null data point pairs in the data used for the computation, then REGR_AVGX returns NULL.
Division by zero results in NULL rather than an error.