[postgis-users] Re: [Geoserver-devel] Postgis estimated_extent completely off the mark?

[Paul Ramsey]

Right, sampling.
Small enough that a random sample has a chance of missing them.   
Northern islands in Alaska, Hawaii, etc.

P

On 20-Mar-07, at 8:13 AM, Andrea Aime wrote:

> Andrea Aime ha scritto:
>> tiger2005fe=# vacuum analyze major_roads;
>> VACUUM
>> tiger2005fe=# select estimated_extent('major_roads','gen_full');
>>                                estimated_extent
>> --------------------------------------------------------------------- 
>> -------
>>   BOX(-136.358154296875 17.6881694793701,-64.7429351806641  
>> 59.4498023986816)
>> (1 row)
>> tiger2005fe=# select extent(gen_full) from major_roads
>> tiger2005fe-# ;
>>                                     extent
>> --------------------------------------------------------------------- 
>> -------
>>   BOX(-170.837387084961 -14.3779020309448,144.914001464844  
>> 66.9222869873047)
>
> Ah, if you're wondering about how this is possible, my guess is that
> estimated_extent is for some reason not considering Hawaii (still  
> USA, but very very far away)
>
> Cheers
> Andrea
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