Hi,
On 2014-02-18 00:43:54 +0900, MauMau wrote:
> Please let me ask you about your performance data on the page:
>
> http://hlinnaka.iki.fi/xloginsert-scaling/padding/
>
> I'm worried about the big increase in max latency. Do you know the cause?
> More frequent checkpoints caused by increased WAL volume thanks to enhanced
> performance?
I don't see much evidence of increased latency there? You can't really
compare the latency when the throughput is significantly different.
> Although I'm not sure this is related to what I'm asking, the following code
> fragment in WALInsertSlotAcquireOne() catched my eyes. Shouldn't the if
> condition be "slotno == -1" instead of "!="? I thought this part wants to
> make inserters to use another slot on the next insertion, when they fail to
> acquire the slot immediately. Inserters pass slotno == -1. I'm sorry if I
> misunderstood the code.
I think you're right.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services
