Hello,

Currently clickhouse is not able to use as primary key/sorting key a nullable column.

If you try this you receive: "Sorting key cannot contain nullable columns".

I think in lot of use-cases the columns are nullable as time this is the standard for specifying that
a value doesn't exist. So lifting this limitation might be important.

I know there is another discussion here: #4332 but this task was closed
for some reasons by the reporter.

Thanks,
Silviu