Re: ext/pgsql: pg_put_line deprecation proposal

Hi, Il 20/05/2024 14:03, David CARLIER ha scritto:

I would like to know if it would be fine to deprecate pg_put_line <http://pg_put_line>. Reasoning is PQPutLine is part of the obsolete list of calls for COPY purpose <https://www.postgresql.org/docs/current/libpq-copy.html#LIBPQ-PQPUTLINE> since the PostgreSQL protocol 3.0 version (supported since postgresql 7.4 released about 20 years ago, see New client-to-server protocol regarding COPY <https://www.postgresql.org/docs/7.4/release-7-4.html>). Related PR <https://github.com/php/php-src/pull/14250>.

I have fond memories of using pg_put_line several years ago! It is true that it's obsolete and although they still work, they are deprecated in libpq. However, I have a few remarks... If you're targeting the protocol 3.0 change, what is deprecated is the pg_put_line('\\.') call that needed to be sent before calling pg_end_copy(). pg_put_line() is used to send data, not just the end message. Hence, the UPGRADING message misrepresents the reason why pg_put_line() is deprecated. In case we really decide to deprecate pg_put_line on the PHP side, so should be pg_end_copy. However we don't provide a full alternative to it, because pg_copy_from only accepts arrays, according to the documentation. As such, there is no real alternative for "streaming" data without storing it all in memory. Unless we provide it, I would vote against deprecating them. My opinion could change if pg_copy_from() worked with generators, but I still think the two function still have a place for those needing low-level access. Cheers -- Matteo Beccati Development & Consulting - http://www.beccati.com/