Hi, On Sat, Nov 22, 2025 at 8:33 PM Sugamoto Shinya <[email protected]> wrote: > > Hi, > > This patch improves the user experience when working with COPY commands by > adding helpful error hints for invalid options. > > Currently, when users make typos in COPY option names or values, they receive > a generic error message without guidance on what went wrong. This patch adds > two types of hints: > > 1. For invalid option names: suggests the closest matching valid option using > the ClosestMatch algorithm (e.g., "foramt" → "Perhaps you meant 'format'") > > 2. For invalid option values: lists all valid values when the set is small > (e.g., for format, on_error, log_verbosity options) > > This follows the pattern already used elsewhere in PostgreSQL for providing > helpful error hints to users.
Given we have 15 COPY options now, it sounds like a reasonable idea. One concern about the patch is that when adding a new COPY option, we could miss updating valid_copy_options list, resulting in providing a wrong suggestion. I think we can consider refactoring the COPY option handling so that we check the given option is a valid name or not by checking valid_copy_options array and then process the option value. > Additionally, this patch corrects a misleading comment for the > convert_selectively option. The comment stated it was > "not-accessible-from-SQL", > but actualy it has been accessible from SQL due to PostgreSQL's generic > option parser. > The updated comment clarifies that while technically accessible, it's > intended for > internal use and not recommended for end-user use due to potential data loss. Hmm, I'm not sure the proposed comment improves the clarification. It's essentially non-accessible from SQL since we cannot provide a valid value for convert_selectively from SQL commands. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
