Re: Add LIMIT option to COPY FROM

On Tuesday, February 3, 2026, Shinya Kato <shinya11(dot)kato(at)gmail(dot)com> wrote:

> Hi hackers,
>
> I'd like to propose adding a LIMIT option to COPY FROM, which limits
> the number of rows to load.
>
> With COPY TO, we can use the LIMIT clause in the query to restrict
> output rows, but COPY FROM has no equivalent way to limit the number
> of rows to load (except using the PROGRAM option with external tools
> like head). This patch resolves that asymmetry.
>
> Syntax example:
> - COPY t FROM STDIN (LIMIT 100);
>
> This feature is useful for:
> - Loading only the first N rows from a huge CSV file to verify data or
> table definitions before a full import

Would want it paired with offset for this use case.

Design:
> - The LIMIT count applies after WHERE filtering and ON_ERROR skipping,
> so it represents the actual number of rows inserted.

Not sure about that choice. I’d go with pre-eval or implement both and
default to pre-eval.

David J.