Re: EXPLAIN BUFFERS

On Thu, Oct 15, 2009 at 11:06 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Thu, Oct 15, 2009 at 7:29 AM, Itagaki Takahiro
>> <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp> wrote:
>>> EXPLAIN BUFFERS only shows 'hit', 'read' and 'temp read' in text format
>>> to fit in display, but xml or json format contains all of them.
>
>> I was very careful when I submitted the machine-readable explain patch
>> to make sure that the choice of which information was displayed was
>> independent of the format, and I think that we should stick with that.
>
> I thought one of the main purposes of adding the machine-readable
> formats was to allow inclusion of information that we thought too
> verbose for the human-readable format.  Whether this info falls into
> that category remains to be seen, but I don't agree with the premise
> that the information content must always be exactly the same.

Hmm. I thought that the purpose of having a generalized options
syntax was that people could have the information they wanted,
independently of the format they chose. Even with a lot of extra
information, the human readable format is still far shorter and more
easily readable than either of the others. If we had gone with the
idea of just dumping everything in the world into the XML format,
you'd be right: but for various reasons we decided against that, which
I'm very happy about.

> FWIW, the patch's output as it stood a few days ago (one extra line per
> node, conditional on a BUFFERS option) did seem perfectly reasonable to
> me, and I don't see the reason to change that format now.

Yep, agreed.

...Robert