Re: Postgres seems to use indexes in the wrong order

Thanks for the tips. I'll make some adjustments

On Tue, Jan 27, 2015 at 8:38 PM, Sameer Kumar <sameer(dot)kumar(at)ashnik(dot)com>
wrote:

>
> On Tue, Jan 27, 2015 at 6:59 AM, Tim Uckun <timuckun(at)gmail(dot)com> wrote:
>
>> The query seems to first use the timestamp column which results in a huge
>> number of records and then filters out using the integer and the macaddr
>> indices. If it was to use the integer index first it would start with a
>> tiny number of records.
>>
>
> ​May be the record distribution of quantiles is skewed.​ Have you tried to
> set more granular statistics for your int column?
>
> The effective_cache_size is one gig. The others are not set so therefore
>> the default.
>
>
> ​Ideally the effective_cache_size can be set to as much as 50-60% of your
> available memory. Also you need to tune your random_page_cost as per the
> behavior of your disk.
>
> https://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server​
>
> ​If these two does not work then may be you should go for setting a more
> granular statistics collection for your specific column-
>
> alter table <table_name> alter column <column_Name> set statistics 1000;
> analyze <table_name>;
>
> ​
>
>
> Best Regards,
>
> *Sameer Kumar | Database Consultant*
>
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