ext/pgsql: pg_put_line deprecation proposal

Hi Matteo,

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.

Thanks for your thoughts, I ve overlooked this.

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/