psycopg3

[petrprikryl]

Hi, are there any plans supporting new psycopg version https://pypi.org/project/psycopg/?

[altaurog]

Hi @petrprikryl , thanks for your interest. TBH I have not made time to explore the new version at all, but I had the impression from the announcements in the psycopg mailing list that it does binary copy using native functionality. Is there still a use for pgcopy with psycopg3?

[petrprikryl]

I think that if you want use binary mode, you still need to handle the data types manually. So there is still room for pgcopy to shine and handle it automatically like it does with psycopg2.

https://www.psycopg.org/articles/2020/11/15/psycopg3-copy/

... which might be more efficient than the textual format, but requires more care with the data types, as the server will not even perform an innocent int4 -> int8 cast for you

https://www.psycopg.org/psycopg3/docs/basic/copy.html#binary-copy

[altaurog]

The documentation is rather sparse. It seems clear that the interface is different, and that some data types are handled. Have you experimented with it? Can you give an example of what does and what doesn’t work? How do you imagine pgcopy would work with psycopg3? Would the pgcopy interface remain the same or would it somehow augment the new copy interface of psycopg3, presumably by automating a call to set_types()?
How would you suggest managing psycopg dependencies? Would this be a distinct pypi package? A different pgcopy version? Or a single library with distinct modules for distinct psycopg versions?

[altaurog]

The ability to send data directly without having to write to a file object looks nice