Re: machine-readable explain output

On Tue, Jun 16, 2009 at 2:12 PM, Tom Lane<tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> The main point here is that we have a pretty good idea of what
> general-purpose client code is likely to want to do with the data, and
> in a lot of cases that does not translate to having to know each node
> type explicitly, so long as it can be categorized.

I agree. I'm just not seeing the need for an *explicit*
categorization contained within the data itself. For one thing, AIUI,
that's the job of things like an XML Schema, which Andres Freund has
already agreed to write, and I would expect that would be of some
value to tool-writers, else why are we creating it? I also think
scalars and lists are recognizable without any particular additional
markup at all, just by introspection of the contents.

Even if we do need some kind of additional markup, I'm reluctant to
try to design it without some feedback from people writing actual
tools about what they find inadequate in the current output. The good
news is that if this patch gets committed fairly quickly after the
release of 8.4, tool authors should have enough time to discover where
any bodies are buried in time to fix them before 8.5. But I'm really
unconvinced that any of this minor formatting stuff is going to rise
to the level of a real problem.

...Robert