On Fri, Jul 23, 2021 at 2:07 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Yes, I'm very well aware of that optimization. While it's certainly
> a hack, it fits within a design that isn't a hack, ie that there are
> common, well-defined cases where we can skip the table rewrite.
> However, for the reasons I explained before, there are no general-purpose
> cases where we can skip an index build on a type-changed column, so
> there is no place to insert a similar hack for the timestamp[tz] case.
Wouldn't the hack just go into CheckIndexCompatible()?
You seemed to think my previous comments about comparing opfamilies
were hypothetical but I think we actually already have the
optimization Peter wants, and it just doesn't apply in this case for
lack of hacks.
Maybe I am missing something.
--
Robert Haas
EDB: http://www.enterprisedb.com