Re: Auto-analyse on insert operations

Le 04/11/2015 14:45, Adrian Klaver a écrit :
> On 11/04/2015 05:32 AM, Bertrand Roos wrote:
>> Hello,
>>
>> I try to configure auto-analyse task with postgresql 9.4.
>> I have the following configuration (default configuration):
>> track_counts = on
>> autovacuum = on
>> log_autovacuum_min_duration = -1
>> autovacuum_max_workers = 3
>> autovacuum_naptime = 300s
>> autovacuum_vacuum_threshold = 50
>> autovacuum_analyze_threshold = 50
>> autovacuum_vacuum_scale_factor = 0.2
>> autovacuum_analyze_scale_factor = 0.2
>> autovacuum_freeze_max_age = 200000000
>> autovacuum_multixact_freeze_max_age = 400000000
>> autovacuum_vacuum_cost_delay = 20ms
>> autovacuum_vacuum_cost_limit = -1
>>
>> With this configuration, I can observe that some tables are
>> auto-analysed, but some others are not. Even if there are millions of
>> insert operations on an empty table (all tables are in cluster mode).
>> In fact it seems that tables with update operations are the only ones
>> that are auto-analysed.
>> I'm quite suprised because the documentation says that daemon check the
>> count of insert, update and delete operations.
>> What could it be the reason ? Why tables which have only update
>> operation, aren't analysed ?
>> Are update operations really taken into account ?
>
> Somewhere you switched actions. You start by saying updated tables are
> being analyzed and end by saying they are not, or are the last
> sentences supposed to refer to inserts?
>
>>
>> Thanks,
>>
>> Bertrand
>>
>>
>>
>
>
Yes the last sentences referred to inserts.
To make it clear, tables with all kinds of operations are auto-analysed.
Table with only insert operations are never auto-analysed.