Re: Ticket 117: Explain Buffers

Le 23/01/2010 15:14, Magnus Hagander a écrit :
> 2010/1/23 Guillaume Lelarge <guillaume(at)lelarge(dot)info>:
>> Hi,
>>
>> This patch handles two new parameters for EXPLAIN: COSTS and BUFFERS.
>> I'm not sure that we need to add support for format. I would like to
>> have your opinion on this?
>
> Not really. The whole idea of using EXPLAIN on the menu is to get the
> graphical output, so I don't see where the user would care aobut the
> format of the text behind it.
>

That was also what I thought... but, if so, why do we propose VERBOSE
option? in this case, we don't get a graphical EXPLAIN, but a textual
EXPLAIN VERBOSE.

> That said, we might want to consider switching to using one of the
> machine readable formats for newer versions, and then just implement
> parsing of these options there. In the end, that should lead to less
> complicated code.. (mind you, I didn't even look at your code so I
> don't know how complex it is :D)
>

We can't switch completely if we want to still have compatibility with
the older releases. Anyways, this is something we'll have to do to ease
the process.

> While you're whacking around the explain code, one thing that has
> always nagged me, is that ANALYZE is an option for EXPLAIN. IMO we
> should have "Explain" and "Explain Analyze" as separate commands,
> because they actually do different things. And then options for things
> like verbose, costs, buffers etc. If we're going to change that ever,
> now is probably the best time :-)
>
> Thoughts?
>

I don't quite get why we should do that. You can already have an EXPLAIN
or an EXPLAIN ANALYZE. Or is it simply to really differentiate them?
because one won't launch the query and the other one will?

--
Guillaume.
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