On 2/22/21 1:01 PM, Tom Lane wrote:
Yeah, and as I pointed out somewhere upthread, trying to replace the whole parser will just end in a maintenance nightmare. The constructs that the parser has to emit are complex, Postgres-specific, and constantly evolving. We are NOT going to promise any sort of cross version compatibility for parse trees.
Absolutely agreed. We cannot promise that the parsetree generated in one version will work with the planner, optimizer and executor of the next. These types of projects will need to pay close attention and more importantly, develop their own regression test suites that detect when something has changed in core. That said, discussion about the parser hook should happen in the other thread.
I don't even expect that we can guarantee that the functions I am trying to allow to be redirected for the wire protocol will be stable forever. libpq V4 may need to change some of the call signatures, which has happened before. For example, the function to send the command completion message to the frontend (tcop/dest.c EndCommand()) changed from 12 to 13.
Regards, Jan -- Jan Wieck Principle Database Engineer Amazon Web Services
