[Qgis-user] Qgis-server recompute always the layer bbox ?

Sun Feb 16 08:16:39 PST 2014

Hi,

I found it.

It was defined in the cmake section:
FindSPATIALITE.cmake

Ok, now I procede to understand if it is really checked.

Regards,

A.

2014-02-16 16:58 GMT+01:00 Andrea Peri <aperi2007 at gmail.com>:

> Hi,
>
> study-ing the qgis code, I see in the spatialite provider there is a
> significative piece of code conditioned by
> some
> #IFDEF SPATIALITE_VERSION_GE_4_0_0
>
> I don't see any option in cmake setting named like this.
>
> Is this a missing ?
>
> Thx,
>
> A.
>
>
>
> 2014-02-14 10:54 GMT+01:00 Andrea Peri <aperi2007 at gmail.com>:
>
> Hi,
>> thx I now start to understand better the question.
>>
>> Infact I'm using spatialite db. A 4.1.1 db spatialite.
>> The spatialite db has an internal statistics table to perform a very fast
>> resolution of the bboxes of single datasets.
>>
>> I always update it using the command:
>>
>> select UpdateLayerStatistics();
>>
>> But the problem is if the client really use that table.
>>
>> Infact I guess more probably the qgis-server don't ask to spatialite the
>> box from this table, but instead do a more usual
>> sql to retrieve is.
>>
>> Hi Sandro,
>> do you know the right query to retrieve the bbox from the statistics
>> table of spatialite 4.1.1 ?
>>
>> I guess suspect that qgis (because it like) to be more compatible with
>> all the oldest (arcaic) version of spatialite, simply avoid to use this
>> table.
>> :)
>>
>> Many thx.
>>
>>
>> Andrea.
>>
>>
>>
>> 2014-02-14 10:34 GMT+01:00 Marco Hugentobler <
>> marco.hugentobler at sourcepole.ch>:
>>
>>  Hi Andrea, Giovanni
>>>
>>> QGIS Server doesn't calculate the bbox itself, but it queries the extent
>>> from the layers. So it can be that certain providers calculate the bbox (of
>>> course only if the layer / capabilities document is not cached).
>>>
>>> For a faster startup, having a persistent cache as Giovanni suggested
>>> might help.
>>>
>>> Regards,
>>> Marco
>>>
>>>
>>> On 14.02.2014 10:18, G. Allegri wrote:
>>>
>>>
>>>>  I don't understand why the qgis-server eed to calculate always the
>>>> bbox.
>>>> In the server project windows,
>>>> qgis ask for the published bbox.
>>>>  Why it don't use it as bbox rather than calculate it on every request
>>>> ?
>>>>
>>>
>>>  Marco, correct me if I'm wrong.
>>> QGIS Server doesn't calculate the BBOX, it parses the layers extents
>>> from the .qgs project and then combine them to obtain the entire BBOX.
>>> The only operation it does is reprojecting the extents to WGS84 to
>>> create the EX_GeographicBoundingBox element.
>>>
>>>  Anyway, in case the project advertises and extent, the combined extent
>>> won't be calculated, so in your case this phase shouldn't be the
>>> bottleneck...
>>>
>>>  giovanni
>>>
>>>
>>>
>>>
>>>
>>>>
>>>>  The FastCGI don't help really.
>>>> In a publishing environment every few hour the instances are restated
>>>> to removed zombi process.
>>>> This mean that every few hours the FastCGI are emptied and reloaded.
>>>> A fastcgi environment mean to load 20 instances of QGIS-server and
>>>> every of them do them own elaboration .
>>>> As the bbox calculation for every layer.
>>>>
>>>> GASP.
>>>> The start could ask about one hours and more.
>>>>
>>>>  Also another problem with the fastcig is that when
>>>>  I change something on a project I need to restart to Web instances to
>>>> dismiss the actual project and reload the new.
>>>>
>>>>  So every change in a qgis project need a restart of all proccess (20
>>>> and so on in a fastcgi enviroment) every with a slow bbox calculation phase.
>>>>
>>>>  mmhh...
>>>>
>>>>  :/
>>>>
>>>>
>>>>
>>>> 2014-02-14 9:13 GMT+01:00 G. Allegri <giohappy at gmail.com>:
>>>>
>>>>>
>>>>>
>>>>>
>>>>> 2014-02-14 Marco Hugentobler <marco.hugentobler at sourcepole.ch>:
>>>>>
>>>>>  Hi Andrea
>>>>>>
>>>>>>
>>>>>> >I suspect that QS try always to recalc the box of every layer.
>>>>>>
>>>>>>  QGIS server caches layers (up to 100, but that can be enhanced using
>>>>>> the environment variable MAX_CACHE_LAYERS).  Furthermore, the
>>>>>> GetCapabilities documents are cached (so no recalculation if using
>>>>>> FastCGI).
>>>>>>
>>>>>>
>>>>>  Thanks Marco, you confirmed what I told Andrea.
>>>>> It would be a good enhancement if caching could be done in a persitent
>>>>> manner (out of memory). We could consider, in the future, to use memcache
>>>>> or something similar.
>>>>>
>>>>>  giovanni
>>>>>
>>>>>  _______________________________________________
>>>>> Qgis-user mailing list
>>>>> Qgis-user at lists.osgeo.org
>>>>> http://lists.osgeo.org/mailman/listinfo/qgis-user
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> -----------------
>>>> Andrea Peri
>>>> . . . . . . . . .
>>>> qwerty àèìòù
>>>> -----------------
>>>>
>>>
>>>
>>>
>>>  --
>>> Giovanni Allegri
>>> http://about.me/giovanniallegri
>>> Twitter: https://twitter.com/_giohappy_
>>> blog: http://blog.spaziogis.it
>>> GEO+ geomatica in Italia http://bit.ly/GEOplus
>>>
>>>
>>>
>>> --
>>> Dr. Marco Hugentobler
>>> Sourcepole -  Linux & Open Source Solutions
>>> Weberstrasse 5, CH-8004 Zürich, Switzerlandmarco.hugentobler at sourcepole.ch http://www.sourcepole.ch
>>> Technical Advisor QGIS Project Steering Committee
>>>
>>>
>>
>>
>> --
>> -----------------
>> Andrea Peri
>> . . . . . . . . .
>> qwerty àèìòù
>> -----------------
>>
>
>
>
> --
> -----------------
> Andrea Peri
> . . . . . . . . .
> qwerty àèìòù
> -----------------
>

-- 
-----------------
Andrea Peri
. . . . . . . . .
qwerty àèìòù
-----------------
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