[Qgis-developer] Geospackage Slow in QGIS

[aperi2007]

Hi Zoltan.

Yes, this is the usual solution in the sqlite world.

I don't like it because is not a scalable solution when there are many 
records and there are relations with other tables.
Also an usual problem is to have a primary key filed with the same 
values of the original table.

The solution
create table as select ...

dont allow to have a primary key field of type integer incremental.

It need a more uggly
create table(...);
insert into .... select .....

But also this don't allow to have the same pk for the same records.

A.

Il 18/08/2014 22:41, Siki Zoltan ha scritto:
> Dear Andrea,
>
> what about using DB Manager's SQL window?
> There you can input an SQL select.
>
> To remove a column in SQLite you can create a new table without the 
> column to delete and then use
> INSERT INTO new_table SELECT ...
>
> Regards,
> Zoltan
>
> On Mon, 18 Aug 2014, Andrea Peri wrote:
>
>> Just to explain why this is an important question.
>
> On a sqlite db is impossible to remove a field.
> So if a table is with two geometry field, it is never see-able from qgis.
> Because is not possible a command like:
>
> alter table remove filed geometry-2;
>
> Bye,
>
> Andrea Peri.
>
>
> 2014-08-18 16:52 GMT+02:00 Andrea Peri <aperi2007 at gmail.com>:
>> Hi,
>>
>> I have changed my opinin.
>> From +1 to +0
>>
>> Infact I discovered just now that gdal driver for spatialite don't
>> seem to support tables with more than 1 geometrt field.
>> Almost on QGIS.
>>
>> Andrea
>>
>>
>> 2014-05-17 22:19 GMT+02:00 Jeremy Palmer <JPalmer at linz.govt.nz>:
>>> I'm wondered why QGIS needs a native SpatiaLite provider and 
>>> connection dialogue any more. Unlike other database providers such 
>>> as PostGIS, Oracle, MSSQL the SpatiaLite provider doesn't seem to 
>>> have anything special that requires a QGIS provider. From a users 
>>> perspective it just adds to the confusion and complexity for adding 
>>> data. Why not just use GDAL/OGR for both Geopackage and Spatialite?
>>>
>>> Cheers
>>> Jeremy
>>> ________________________________________
>>> From: Stefan Keller [sfkeller at gmail.com]
>>> Sent: Sunday, 18 May 2014 12:24 a.m.
>>> To: Martin Dobias
>>> Cc: Jeremy Palmer; qgis-developer at lists.osgeo.org
>>> Subject: Re: [Qgis-developer] Geospackage Slow in QGIS
>>>
>>> Hi Martin
>>>
>>> It has a different binary encoding compared to Spatialite.
>>> And in addition it integrates raster tiles (MBTiles) and metadata.
>>>
>>> -S.
>>>
>>>
>>> 2014-05-17 14:10 GMT+02:00 Martin Dobias 
>>> <wonder.sk at gmail.com<mailto:wonder.sk at gmail.com>>:
>>> Hi
>>>
>>> On Sat, May 17, 2014 at 2:32 PM, Jeremy Palmer 
>>> <JPalmer at linz.govt.nz<mailto:JPalmer at linz.govt.nz>> wrote:
>>>> I've just been using the new implementation of Geopackage in QGIS 
>>>> :) However each map render or feature info is very slow for large 
>>>> database files - even with the new GDAL/OGR Geopackage spatial 
>>>> index support. Each time QGIS renders a new map view or executes a 
>>>> feature info it re-opens the Geopackage file in 
>>>> QgsOgrFeatureIterator via OGROpen, and the Geopackage driver open 
>>>> method runs PRAGMA integrity_check which is very slow (4 secs with 
>>>> my 2GB test file). This integrity check is actually a Geopackage 
>>>> requirement.
>>>>
>>>> How can this be fixed? At the in QGIS or GDAL/OGR level?
>>>
>>> Actually I am wondering how different is the format of GeoPackage from
>>> the format of SpatiaLite... we could use our native SpatiaLite
>>> provider also for GeoPackage files if they are close enough. Any
>>> ideas?
>>>
>>> Regards
>>> Martin
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>>
>>
>>
>> -- 
>> -----------------
>> Andrea Peri
>> . . . . . . . . .
>> qwerty ˙˙˙˙˙˙˙˙˙˙
>> -----------------
>
>
>