Support TIMESTAMP_NS, TIMESTAMP_MS & TIMESTAMP_S

[destrex271]

Draft PR to support TIMESTAMP_NS, TIMESTAMP_MS & TIMESTAMP_S types available in duckdb in postgres.

Fixes #283

[destrex271]

Insert statements executed from postgres on tables in motherduck are working as expected for TIMESTAMP_MS & TIMESTAMP_S.

-- Tables created in Motherduck
CREATE TABLE timestamps_ms_tbl(a timestamp_ms);
CREATE TABLE timestamps_s_tbl(a timestamp_s);
-- ------------------------------------------------------------------------

-- Insert statements executed from postgres
INSERT INTO timestamps_ms_tbl VALUES('1992-12-12 12:12:12.1989898'::TIMESTAMP);
INSERT INTO timestamps_s_tbl VALUES('1992-12-12 12:12:12.1989898'::TIMESTAMP);

-- Selecting Data from mother duck via postgres
-- -------------------------------------------------------------------
SELECT * FROM timestamps_ms_tbl; 
-- Output:
-- 1992-12-12 12:12:12.198

SELECT * FROM timestamps_s_tbl;
-- Output
-- 1992-12-12 12:12:12

Currently working on converting TIMESTAMP_MS selected from duckdb into Postgres TIMESTAMP type

[destrex271]

@JelteF, I tested this against some tables in Motherduck, but I’m not sure how to go about writing regression tests for this. From what I understand, the type_support tests are queries run from within PostgreSQL. Since this PR doesn’t add any new types to Postgres, I’m a bit confused about the best way to proceed.

[destrex271]

Also unrelated to this issue, I noticed another problem while working on this:

As you can see, for some reason on motherduck timestamp_ns is being compressed to timestamp with micro second precision only.

[JelteF]

I tested this out manually using MotherDuck, and it works well. Code also looks good, but I left a few small comments on how to fix CI.

Regarding how to add similar automated tests. I don't think that's possible indeed. But one thing we can do is at least test the conversion from DuckDB to Postgres by using the duckdb.query function that was introduced in #531 (which I merged half an hour ago):

SELECT * FROM duckdb.query($$ SELECT '1992-12-12 12:12:12.123456789'::TIMESTAMP_NS as ts $$);

That query works on this branch, but not on main. If you can add similar queries for all the newly supported types then I think we can merge this.

[JelteF]

needs a default case to silence the compiler warning

[JelteF]

You need to run make format to solve the formatting warning.

[destrex271]

I tested this out manually using MotherDuck, and it works well. Code also looks good, but I left a few small comments on how to fix CI.

Regarding how to add similar automated tests. I don't think that's possible indeed. But one thing we can do is at least test the conversion from DuckDB to Postgres by using the duckdb.query function that was introduced in #531 (which I merged half an hour ago):

SELECT * FROM duckdb.query($$ SELECT '1992-12-12 12:12:12.123456789'::TIMESTAMP_NS as ts $$);

That query works on this branch, but not on main. If you can add similar queries for all the newly supported types then I think we can merge this.

Cool I'll update this accordingly.