[Qgis-developer] QGIS Multi-threaded Rendering

Martin Dobias wonder.sk at gmail.com
Mon Jan 6 04:31:57 PST 2014

Hi Andreas

On Fri, Dec 13, 2013 at 8:31 PM, Andreas Neumann <a.neumann at carto.net> wrote:
> Hi Martin,
> I guess I am also running into the PostgreSQL issue. In general my
> PostgreSQL based projects with many layers freeze after a very short
> time, while the SpatiaLite based projects work very nicely.
> Too many PostgreSQL connections? Can we limit the PostgreSQL connections
> or can you better re-use existing connections?

A quick followup - today I have pushed some changes that introduce a
connection pool for PostgreSQL. This should remove the problem with
too many connections. It limits the maximum number of concurrent
connections from one QGIS instance to four. Also, when the connections
are not used for some time, they get closed to save resources (right
now it is after one minute).

Please test and let me know if things work better now.

I will probably also look at pooling of SpatiaLite connections - right
now the queries within SQLite are serialized, so within one SpatiaLite
database you will not see any performance gain with parallel


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