Hi Sergei!
nice :) i'm reading about it
just one doubt i didn't understand everything yet
there's a read time and a scan time, what the difference? read = sequencial read and scan = non sequencial read? or something like table read cost, index read cost?


2014-05-27 5:41 GMT-03:00 Sergei Golubchik <serg@mariadb.org>:
Hi, Roberto!

On May 26, Roberto Spadim wrote:
> hi guys, one question, that maybe at the right time could be answered...
> with the new cost model, maybe at explain we could have a new information
> about how many time we will expend? and maybe something like, estimate time
> / executed time (via show warnings?)
> i will read the patch about this work, and check if i could help with
> something like this
> is it interesting?

First, it's not about creating a new cost model. Only about providing
more adequate real-life values to certain parameters in the current cost
model.

And yes, the work could, possibly, help to estimate the query execution
time. Although this wasn't the goal, we only wanted to find correct
relative values, not absolute.

Regards,
Sergei




--
Roberto Spadim
SPAEmpresarial
Eng. Automação e Controle