Re: Centos 6.9 and centos 7

Did you run ANALYZE on your tables before the test?

On 4 December 2017 at 16:01, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com> wrote:
>
> On 12/04/2017 02:19 PM, Nicola Contu wrote:
> ...>
>> centos 7 :
>>
>> dbname=# \timing Timing is on. cmdv3=# SELECT id FROM
>> client_billing_account WHERE name = 'name'; id ------- ***** (1 row)
>> Time: 3.884 ms
>>
>> centos 6.9
>>
>> dbname=# SELECT id FROM client_billing_account WHERE name = 'name'; id
>> ------- ***** (1 row) Time: 1.620 ms
>>
>
> We need to see EXPLAIN (ANALYZE,BUFFERS) for the queries.
>
> Are those VMs or bare metal? What CPUs and RAM are there? Have you
> checked that power management is disabled / cpufreq uses the same
> policy? That typically affects short CPU-bound queries.
>
> Other than that, I recommend performing basic system benchmarks (CPU,
> memory, ...) and only if those machines perform equally should you look
> for issues in PostgreSQL. Chances are the root cause is in hw or OS, in
> which case you need to address that first.
>
> regards
>
> --
> Tomas Vondra http://www.2ndQuadrant.com
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>

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