Re: review: pgbench - aggregation of info written into log

Hi,

attached is a v5 of this patch. Details below:

On 8.12.2012 16:33, Andres Freund wrote:
> Hi Tomas,
>
> On 2012-11-27 14:55:59 +0100, Pavel Stehule wrote:
>>> attached is a v4 of the patch. There are not many changes, mostly some
>>> simple tidying up, except for handling the Windows.
>
> After a quick look I am not sure what all the talk about windows is
> about? instr_time.h seems to provide all you need, even for windows? The
> only issue of gettimeofday() for windows seems to be that it is that its
> not all that fast an not too high precision, but that shouldn't be a
> problem in this case?
>
> Could you expand a bit on the problems?

As explained in the previous message, this is an existing problem with
unavailable timestamp. I'm not very fond of adding Linux-only features,
but fixing that was not the goal of this patch.

>>>> * I had a problem with doc
>
> The current patch has conflict markers in the sgml source, there seems
> to have been some unresolved merge. Maybe that's all that causes the
> errors?
>
> Whats your problem with setting up the doc toolchain?

Yeah, my fault because of incomplete merge. But the real culprit was a
missing refsect2. Fixed.

>
>> issues:
>>
>> * empty lines with invisible chars (tabs) + and sometimes empty lines
>> after and before {}

Fixed (I've removed the lines etc.)

>>
>> * adjustment of start_time
>>
>> +                                               * the desired interval */
>> +                                               while (agg->start_time
>> + agg_interval < INSTR_TIME_GET_DOUBLE(now))
>> +
>> agg->start_time = agg->start_time + agg_interval;
>>
>> can "skip" one interval - so when transaction time will be larger or
>> similar to agg_interval - then results can be strange. We have to know
>> real length of interval
>
> Could you post a patch that adresses these issues?

So, in the end I've rewritten the section advancing the start_time. Now
it works so that when skipping an interval (because of a very long
transaction), it will print lines even for those "empty" intervals.

So for example with a transaction file containing a single query

   SELECT pg_sleep(1.5);

and an interval length of 1 second, you'll get something like this:

1355009677 0 0 0 0 0
1355009678 1 1501028 2253085056784 1501028 1501028
1355009679 0 0 0 0 0
1355009680 1 1500790 2252370624100 1500790 1500790
1355009681 1 1500723 2252169522729 1500723 1500723
1355009682 0 0 0 0 0
1355009683 1 1500719 2252157516961 1500719 1500719
1355009684 1 1500703 2252109494209 1500703 1500703
1355009685 0 0 0 0 0

which is IMHO the best way to deal with this.

I've fixed several minor issues, added a few comments.

regards
Tomas