Re: [PATCH] pgbench --throttle (submission 7 - with lag measurement)

Поиск
Список
Период
Сортировка
От Tatsuo Ishii
Тема Re: [PATCH] pgbench --throttle (submission 7 - with lag measurement)
Дата
Msg-id 20130718.123408.181246741123953980.t-ishii@sraoss.co.jp
обсуждение исходный текст
Ответ на Re: [PATCH] pgbench --throttle (submission 7 - with lag measurement)  (Greg Smith <greg@2ndQuadrant.com>)
Ответы Re: [PATCH] pgbench --throttle (submission 7 - with lag measurement)  (Greg Smith <greg@2ndQuadrant.com>)
Список pgsql-hackers
> On 7/17/13 9:16 PM, Tatsuo Ishii wrote:
>> Now suppose we have 3 transactions and each has following values:
>>
>> d(0) = 10
>> d(1) = 20
>> d(2) = 30
>>
>> t(0) = 100
>> t(1) = 110
>> t(2) = 120
>>
>> That says pgbench expects the duration 10 for each
>> transaction. Actually, the first transaction runs slowly for some
>> reason and the lag = 100 - 10 = 90. However, tx(1) and tx(2) are
>> finished on schedule because they spend only 10 (110-10 = 10, 120-110
>> = 10). So the expected average lag would be 90/3 = 30.
> 
> The clients are not serialized here in any significant way, even when
> they shared a single process/thread.  I did many rounds of tracing
> through this code with timestamps on each line, and the sequence of
> events here will look like this:

My example is for 1 client case. So concurrent clients are not the
issue here.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp



В списке pgsql-hackers по дате отправления:

Предыдущее
От: Andrew Gierth
Дата:
Сообщение: Proposal/design feedback needed: WITHIN GROUP (sql standard ordered set aggregate functions)
Следующее
От: Amit Kapila
Дата:
Сообщение: Re: ALTER SYSTEM SET command to change postgresql.conf parameters (RE: Proposal for Allow postgresql.conf values to be changed via SQL [review])