Re: Physical Log Boundedness...
Greg wrote:
>
>To clarify: by bounded, I mean being limited by the ability to write to
>the disk fast enough to not block the CPU waiting for the I/O to
>complete.
>
>>
>>Anybody got some good tricks to relieve Physical log boundedness when
>>doing massive Insert/Update/Deletes???
>>
>> Thanks - Greg
Greg,
try using a huge physical log buffer. How useful this turns out to be
depends on other factors - like checkpoint frequency and general
page-flushing activity. Monitor the average number of pages per flush
with 'onstat -d'.
You can lower general page-flushing activity with a long checkpoint
interval and high values for values for LRU_MAX_DIRTY and LRU_MIN_DIRTY.
However, when you do this, human users on the system will be subject to
periodic freeze-ups, when a checkpoint freezes the buffer pool while
flushing thousands of pages.
But for massive updates/insert/delete, hey, this is just fine!
--
-- Jake Salomon
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