Re: write scalability

On Tue, Jul 26, 2011 at 12:24 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Tue, Jul 26, 2011 at 11:40 AM, Pavan Deolasee
> <pavan(dot)deolasee(at)gmail(dot)com> wrote:
>> On Tue, Jul 26, 2011 at 9:07 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>>> On Mon, Jul 25, 2011 at 10:14 PM, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:
>>>> On 07/25/2011 04:07 PM, Robert Haas wrote:
>>>>>
>>>>> I did 5-minute pgbench runs with unlogged tables and with permanent
>>>>> tables, restarting the database server and reinitializing the tables
>>>>> between each run.
>>>>
>>>> Database scale?  One or multiple pgbench worker threads?  A reminder on the
>>>> amount of RAM in the server would be helpful for interpreting the results
>>>> too.
>>>
>>> Ah, sorry.  scale = 100, so small.  pgbench invocation is:
>>>
>>
>> It might be worthwhile to test only with the accounts and history
>> table and also increasing the number of statements in a transaction.
>> Otherwise the tiny tables can quickly become a bottleneck.
>
> What kind of bottleneck?
>

So many transactions trying to update a small set of rows in a table.
Is that what we really want to measure ? My thinking is that we might
see different result if they are updating different parts of the table
and the transaction start/stop overhead is spread across few
statements.

Thanks,
Pavan

--
Pavan Deolasee
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