Re: [HACKERS] Partition-wise join for join between (declaratively)partitioned tables

On Tue, Jul 25, 2017 at 1:31 AM, Rafia Sabih
<rafia.sabih@enterprisedb.com> wrote:
> - other queries show a good 20-30% improvement in performance. Performance
> numbers are as follows,
>
> Query| un_part_head (seconds) | part_head (seconds) | part_patch (seconds) |
> 3 | 76 |127 | 88 |
> 4 |17 | 244 | 41 |
> 5 | 52 | 123 | 84 |
> 7 | 73 | 134 | 103 |
> 10 | 67 | 111 | 89 |
> 12 | 53 | 114 | 99 |
> 18 | 447 | 709 | 551 |

Hmm.  This certainly shows that benefit of the patch, although it's
rather sad that we're still slower than if we hadn't partitioned the
data in the first place.  Why does partitioning hurt performance so
much?

Maybe things would be better at a higher scale factor.

When reporting results of this sort, it would be good to make a habit
of reporting the number of partitions along with the other details you
included.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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