Bug report #19203
QGIS 3.0 postgis rendering
|Affected QGIS version:||3.0.3||Regression?:||No|
|Operating System:||Windows 7||Easy fix?:||No|
|Pull Request or Patch supplied:||No||Resolution:|
|Crashes QGIS or corrupts data:||No||Copied to github as #:||27032|
This was previously reported but no solution was given. At this point I can't use 3.0 because the rendering from postgis is too slow.
"I have added data from PostGIS in Version 2.18 and the one data set loads in about 2 seconds. With the new 3.0 version, it takes 2 minutes to load that same data layer. All my data sets load really slow in Version 3.0. Not sure what the difference is from 2.18 to 3.0"
I also can't connect to the database using the DB manager, but that is a separate issue I believe.
#2 Updated by Angie Rudolph about 2 years ago
There is significant differences in the query logs.
Primary in 3.0 it is requesting each object individually
(see line 130 in attached postgresql3.0.log)
2018-06-15 14:52:59.847 MDT  [email protected] LOG: statement: FETCH FORWARD 1 FROM qgis_1
In 2.18 it requests 2000 objects (see line 107 in attached postgresql2.18.log)
2018-06-15 15:04:03.519 MDT  [email protected] LOG: statement: FETCH FORWARD 2000 FROM qgis_1
I have attached the two log files for your reference. Let me know if I should be logging something different.