Re: Learning EXPLAIN

Dude,

You can rest assured that at least the Brazilians members will always know
based on your last name you are not the same :-).

What's the point of explaining that anyways? Got curious.

As to what pertains to the topic:

This is another simple yet effective doc:

https://wiki.postgresql.org/images/4/45/Explaining_EXPLAIN.pdf

Execution plans are tricky and reading them accurately to make good
decisions require a lot of experience and awareness of the situation. It
does not only require that you know how to read the tool itself but also
know how the DB and schemas have been designed, if stats are up to date,
how tables are populated, frequency and type of queries, adequate indexing
in place, the hardware it sits on, etc.

It's a mix of science, broaden knowledge, perspicacity, and why not
say, it's an art.

Have a great weekend.

___________________________________________________________________________
Gustavo Velasquez
+1 (256) 653-9725

On Fri, Dec 8, 2017 at 7:32 AM, Flavio Henrique Araque Gurgel <
fhagur(at)gmail(dot)com> wrote:

>
> Em sex, 8 de dez de 2017 às 14:20, Guillaume Lelarge <
> guillaume(at)lelarge(dot)info> escreveu:
>
>> Hi,
>>
>> 2017-12-08 2:12 GMT+01:00 Flávio Henrique <yoshimit(at)gmail(dot)com>:
>>
>>> Hi experts!
>>>
>>> I read this nice article about Understanding EXPLAIN [1] weeks ago that
>>> opened my mind about the tool, but it seems no enough to explain a lot of
>>> plans that I see in this list.
>>>
>>
>> Thanks.
>>
>> I often read responses to a plan that are not covered by the article.
>>>
>>> I need/want to know EXPLAIN better.
>>>
>>> Can you kindly advise me a good reading about advanced EXPLAIN?
>>>
>>>
>> There's not much out there. This document was written after reading this
>> list, viewing some talks (you may find a lot of them on youtube), and
>> reading the code.
>>
>> I intend to update this document, since I learned quite more since 2012.
>> Though I didn't find the time yet :-/
>>
>> Anyway, thanks.
>>
>>
> Hello all
>
> I would like to make clear that there are two "Flavio Henrique" on the
> lists, me beeing one of them, I'd like to say that I'm not the OP.
> A bit off-topic anyway, thanks for understanding.
>
> Flavio Gurgel
>
>