[gdal-dev] GDAL may create slow GPKG/SQLite indexes

[a.furieri at lqt.it]

On Mon, 9 Jun 2014 07:31:05 +0000 (UTC), Jukka Rahkonen wrote:
> Perhaps this has something to do with different SQLite versions 
> included in
> GDAL and Spatialite-gui. My GDAL is v.2.0 Win-64 build from 
> gisinternals.
>
> This kind of behaviour is nasty when planning to build well optimized 
> and
> indexed GeoPackage datafiles for the end users.
>

Hi Jukka,

there was a major change affecting all recent versions of SQLite
starting since 3.8.0 (2013-08-26) [1]

a brand new NGQP (New Generation Query Planner) was introduced:
in the vast majority of cases NGQP will effectively imply
choosing a more efficient query strategy.
but unhappily there are few exceptions (worst cases) where
NGQP could possibly follow a very inefficient query strategy;
please read sections 4.0, 4.1 and 4.2 of the aforementioned
sqlite's document for more details.

[1] http://www.sqlite.org/queryplanner-ng.html

bye Sandro