Hi, On 2021-09-15 16:35:53 -0400, Jonah H. Harris wrote: > On Wed, Sep 15, 2021 at 3:55 PM Andres Freund <and...@anarazel.de> wrote: > > On 2021-09-15 12:57:00 -0400, Tom Lane wrote: > > Agreed - it doesn't make sense to me to have a hook that only replaces raw > > parsing, without also hooking into parse-analysis. ISTM that the least a > > patchset going for a parser hook would have to do is to do sufficient > > restructuring so that one could hook together into both raw parsing and > > analysis. It could still be two callbacks, but perhaps we'd ensure that > > they're both set. > > > > This is a bad example as it doesn't require semantic analysis from > Postgres.
"it"? I assume you mean a different type of join? If so, I'm highly doubtful - without semantic analysis you can't really handle column references. > While most of the tools out there tend to do simple replacement, > this can be done within a custom parser by simply walking its own AST, > evaluating join conditions against the expression, and rewriting the join > accordingly. Or, do you have an example that couldn't be done this way > within a custom parser? You cannot just "evaluate conditions" in a raw parse tree... You don't even know what things are functions, columns etc, nor to what relation a column belongs. Greetings, Andres Freund
