Обсуждение: Pgbench with -f and -S

-
robins

> Pgbench allows -f and -S combinations together where the doc says that -S
> effectively uses the internal select-only script.
>
> Is it okay to assume that -f is disregarded here? Or are they run in
> round-robin fashion (although then, how does it know which read-only part
> of my script to run?) or something else like that?
>
> Effectively, I think it should raise NOTICE that -f is useless here.

For the future 9.6, scripts options are cumulatives, so -f & -S can be 
combined.

Indeed, for the <= 9.5 it seems that some options are silently ignores, 
when combining -S/-f, only the last one is kept, it should be warned 
about.

-- 
Fabien.

>> For the future 9.6, scripts options are cumulatives, so -f & -S can be
>> combined.
>>
>> Indeed, for the <= 9.5 it seems that some options are silently ignores,
>> when combining -S/-f, only the last one is kept, it should be warned about.
> ​
> ​Thanks Fabien, for confirming about the missing warning.
>
> Also, by 'combined' I think you mean that both (built-in SELECTs & Custom
> Script) run, although the dev docs don't (yet) say anything about that.

Hmmm... I think it does implicitely, with "add" and "and" in the 
following:

From http://www.postgresql.org/docs/devel/static/pgbench.html:
  -b scriptname[@weight]  Add the specified builtin script to the list of executed scripts. [...]

Idem -f.

And later at the beginning of the Notes:
  pgbench executes test scripts chosen randomly from a specified list.  They include built-in scripts with -b and
user-providedcustom scripts with -f.  [...]
 

-- 
Fabien.