Re: Extensibility of the PostgreSQL wire protocol

"Jonah H. Harris" <jonah.harris@gmail.com> writes:
> On Wed, Feb 10, 2021 at 1:10 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> ...  If we start having
>> modes for MySQL identifier quoting, Oracle outer join syntax, yadda
>> yadda, it's going to be way more of a maintenance nightmare than some
>> hook functions.  So if we accept any patch along this line, I want to
>> drive a hard stake in the ground that the answer to that sort of thing
>> will be NO.

> Actually, a substantial amount can be done with hooks. For Oracle, which is
> substantially harder than MySQL, I have a completely separate parser that
> generates a PG-compatible parse tree packaged up as an extension. To handle
> autonomous transactions, database links, hierarchical query conversion,
> hints, and some execution-related items requires core changes.

That is a spot-on definition of where I do NOT want to end up.  Hooks
everywhere and enormous extensions that break anytime we change anything
in the core.  It's not really clear that anybody is going to find that
more maintainable than a straight fork, except to the extent that it
enables the erstwhile forkers to shove some of their work onto the PG
community.

My feeling about this is if you want to use Oracle, go use Oracle.
Don't ask PG to take on a ton of maintenance issues so you can have
a frankenOracle.

                        regards, tom lane