| From: | Gerald Fontenay <gvfontenay(at)lbl(dot)gov> | 
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org | 
| Subject: | Re: Strange explain on partitioned tables | 
| Date: | 2010-07-24 06:29:37 | 
| Message-ID: | 4C4A8851.3090608@lbl.gov | 
| Views: | Whole Thread | Raw Message | Download mbox | Resend email | 
| Thread: | |
| Lists: | pgsql-performance | 
Joshua D. Drake wrote:
> On Fri, 2010-07-23 at 15:03 -0700, Gerald Fontenay wrote:
>   
>>> The PostgreSQL partitioning system is aimed to support perhaps a 
>>> hundred inherited tables.  You can expect to get poor performance on 
>>> queries if you create 1000 of them. 
>>>       
>> Hi,
>>
>> Why is that you would expect poor performance for say 1000 or more? I 
>> have a ~1000 inherited tables and I don't see any significant slowdowns. 
>> I only ever access a single inherited table at a time though in this 
>> situation. I suppose I am using inheritance only for organization in 
>> this case...
>>     
>
> It is variable based on workload and as I recall has to do with the
> planning time. As the number of children increases, so does the planning
> time.
>
>   
 
 I do not execute queries against the parent and children tables.
It became obvious that this can be quite slow.
I am asking specifically if I can expect problems in *that* situation, again, where I directly query a single child table only and where I may have thousands. Just like a any other single table query, no?
Thank you,
Gerald
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Craig Ringer | 2010-07-24 06:36:19 | Re: Pooling in Core WAS: Need help in performance tuning. | 
| Previous Message | Craig Ringer | 2010-07-24 06:23:01 | Re: Pooling in Core WAS: Need help in performance tuning. |