| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | "Craig A(dot) James" <cjames(at)modgraph-usa(dot)com> |
| Cc: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Poor performance o |
| Date: | 2006-03-22 04:31:43 |
| Message-ID: | 10012.1143001903@sss.pgh.pa.us |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers pgsql-performance |
"Craig A. James" <cjames(at)modgraph-usa(dot)com> writes:
> Tom Lane wrote:
>> Given the sizes of the tables involved, you'd likely have to boost up
>> work_mem before the planner would consider a hash join. What nondefault
>> configuration settings do you have, anyway?
> shared_buffers = 20000
> work_mem = 32768
> effective_cache_size = 300000
So for a 6M-row table, 32M work_mem would allow ... um ... 5 bytes per
row. It's not happening :-(
Try boosting work_mem by a factor of 100 and seeing whether a hash-based
join actually wins or not. If so, we can discuss where the sane setting
really falls, if not there's no point.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Qingqing Zhou | 2006-03-22 04:32:32 | Re: PANIC: heap_update_redo: no block |
| Previous Message | Tom Lane | 2006-03-22 03:56:02 | Re: PANIC: heap_update_redo: no block |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Qingqing Zhou | 2006-03-22 06:20:39 | Re: WAL logging of SELECT ... INTO command |
| Previous Message | Jeff Frost | 2006-03-22 02:48:26 | motherboard recommendations |