Re: [HACKERS] pgbench tap tests & minor fixes

Hello,

> st->cnt -- number of transactions finished successed or failed, right?

Or *skipped*. That is why I changed the declaration comment.

> one iteration of for(;;) is for one transaction or really less. Right?

No, under -R -L late schedules are simply skipped.

> We can't process two tansactions in one iteration of this loop. So we 
> can't increase st->cnt more then once during one iteration?

Yes we can, if they are skipped because the scheduling was too late to 
execute them on time.

>                processXactStats(thread, st, &now, true, agg);
>
> Let's imagine that thread->throttle_trigger is  now_us - 10 000,
> latency_limit is 5 000 and throttle_delay is 100
>
> How many times you would call  processXactStats in this while loop?

Around 100 times to catch up.

> And each time it would do st->cnt++

Yep. The "true" argument tells the stats that the transaction was skipped, 
though. It just counting late transaction that could not be processed.

> And this while loop is inside for(;;) in which as I said above we can do 
> st->cnt++ not more than once. I see no logic here.

The logic is that at most one *real* transaction is actually performed in 
the for, but there may be any number of "skipped" (unexecuted) ones, which 
is fine.

> PS This is a fast reply. May be it will make things clear fast wither for me
> or for you. I will carefully answer your full letter tomorrow (I hope nothing
> will prevent me from doing it)

Today was a holiday in France. Tomorrow is not.

-- 
Fabien.