Hi, Followers.
I have a problem with CALCITE-4924
<https://issues.apache.org/jira/browse/CALCITE-4924>. As described in the
JIRA, These functions return the wrong data type in some scenes. So I think
a long time about how to infer the more accurate data type.
Finally, I prepare to calculate the data type. Because this method will
make many changes, I want to ask you for advice before. For example :
------> REGR_SXX(x, y) → REGR_COUNT(x, y) * VAR_POP(y)
When I infer the REGR_SXX return type, I calculate the REGR_COUNT type and
VAR_POP type and multiply the two types to get the REGR_SXX type.
The rule same as AggregateReduceFunctionsRule.
Besides, I prepare a Draft PR
<https://github.com/apache/calcite/pull/2826/files> for quick understanding.
