[Qgis-user] QGIS slow performance with PostgreSQL/PostGIS

[Morten Storm]

Hi again,

On our quest for better performance mentioned below we have used the debugging/development tools panel to monitor startup and project load time.

Here we on several occasions have noted a fair amount of time spent on ‘Reading external settings’ (up to 17 sec) during project load. Does anybody know the exact processes going on during this?? Exactly what external settings are being read?

Thanks in advance!


Kind regards,

Morten Storm
Chefkonsulent

[cid:image001.png at 01D798CC.F9FD33F0]<http://www.artogis.dk/>
[cid:image002.png at 01D798CC.F9FD33F0]
Fra: Qgis-user <qgis-user-bounces at lists.osgeo.org> På vegne af Morten Storm
Sendt: 23. august 2021 10:05
Til: qgis-user at lists.osgeo.org
Emne: [Qgis-user] QGIS slow performance with PostgreSQL/PostGIS

We experience slow performance in QGIS 3.xx (also tried with 3.20 with no noticable improvement). Data are stored in a PostgreSQL/PostGIS database and we have done enough testing that we do not believe that the database is the problem. And all tables are setup with spatial indexes and attribute indexes on fields used for filtering and visualization.

The slowness shows its ugly face when for instance the program freezes for a long time when performing even simple tasks, like e.g. saving the project or moving the map in the window.

The issue increases with the size of the project and we don't experience any noticable slowness in small to medium sized projects. The project I tested with most recently was about 4-5 MB when saved in QGIS 3 format (qgz) and about 40 MB when saved unzipped (qgs).

The project contains perhaps +/-100 vector layers from PostgreSQL/PostGIS data and a few online layers (basemap, etc.). Has anybody encountered anything similar and perhaps even found the reason and a solution? Or is anybody aware of some software that could help debug/analyze QGIS to find out what takes all that time?

As implied earlier we have tried and tested a lot including running QGIS on the same physical server as the database to eliminate network issues.


Kind regards,

Morten Storm
Chefkonsulent

[cid:image001.png at 01D798CC.F9FD33F0]<http://www.artogis.dk/>
[cid:image002.png at 01D798CC.F9FD33F0]
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