Re: Problems with question marks in operators (JDBC, ECPG, ...)

I think deprecation doesn't necessarily imply removal. It seems that the two operators could exist together by creating a second operator with the same characteristics as suggested by Frank Heikens in this post:
http://stackoverflow.com/questions/27573778/postgresql-jsonb-and-jdbc/27580137#27580137

This would also make it easier to backport these operators into existing installations (even on 9.4), thereby making the transition easier.

I don't know enough about PostgreSQL's implementation, but I presume this is effectively just giving an alias for the same operation, and hopefully, the query engine could benefit from indices created using either notations interchangeably. (This is probably the most important feature when changing one notation for another.)

In addition, the argument regarding the time it can take users to upgrade works both ways. If I understood correctly from your message yesterday, you've only implemented the latest workaround using \? in DBD::Pg quite recently, which would equally require users to be able to upgrade to a more recent version of DBD::Pg (or PHP/PDO where the workaround doesn't seem to be implemented at all yet). Admittedly, I guess it might often be easier to upgrade the client side than the database server, but I'm not sure that is always the case (some frontends can potentially be awkward to update, whereas a database upgrade can be smoother... It varies...).