Columnar Format Export in Postgres

Hey Postgres team,

I have been working on adding support for columnar format export to
Postgres to speed up analytics queries.
I've created an extension that achieves this functionality here
<https://github.com/sushrut141/pg_analytica>.

I"m looking to improve the performance of this extension to enable drop-in
analytics support for Postgres. Some immediate improvements I have in mind
are:
- Reduce memory consumption when exporting table data to columnar format
- Create a native planner / execution hook that can read columnar data.

It would be very helpful if you could take a look and suggest improvements
to the extension.
Hopefully, this extension can be shipped by default with postgres at some
point in the future.

Thanks,
Sushrut