← Back to team overview

maria-discuss team mailing list archive

Re: EXPLAIN and CONNECT

 

nice :) no problems in this case
i wasn't considering this
i will check if documentations have this, serious i don't remember if
something simple like this is explained and i never checked before :)

if i don't found this information, i will reply here


2014-05-26 19:52 GMT-03:00 Sergei Golubchik <serg@xxxxxxxxxxx>:

> Hi, Roberto!
>
> On May 26, Roberto Spadim wrote:
> > maybe include at extra "estimative rows count"
> > just to understand what happened
>
> Row count in the EXPLAIN output is *always* an estimation, there is no
> need to specify it explicitly because it is always the case.
>
> > > I suppose you've seen the answer in the bug report. But just for the
> > > sake of completeness I repeat it here.
> > >
> > > CONNECT does not read rows several times. But in the CSV file format,
> > > rows can have different lengths and CONNECT cannot directly know how
> > > many rows your table has. So, it *estimates* the number of rows by
> > > dividing the file length by the minimal row length (which it can
> > > calculate from the table definition).
>
> Regards,
> Sergei
>



-- 
Roberto Spadim
SPAEmpresarial
Eng. Automação e Controle

Follow ups

References