8. Frequently Asked Question¶
What are the differences between QGIS Desktop and QGIS Server?
QGIS Desktop has a graphical user interface and allows you to create and modify maps. QGIS Server is a server application serving your QGIS project files to end user applications via OGC web services like WMS, WFS, etc..
What is OGC?
The OGC (Open Geospatial Consortium) is an international not for profit organization committed to making quality open standards for the global geospatial community.
Name some other web mapping servers?
ArcGIS server, Geoserver, Mapserver, Mapnik etc.
How to compare QGIS server to other web mapping servers? (2021/01/01)
Features
QGIS Server
GeoServer
ArcGIS Server
Since
2006
2001
1999
Licence
GPL
GPL
commercial
Commercial support
Multiple companies
Multiple companies
ESRI and its vendors network
Technology
C++/python
Java
C++
Tile cache
yes
yes (via GeoWebCache)
yes
3D
No
No
Yes
Querying
FES (2.0) and OGC (1.0) filters
CQL and OGC filters
OGC filters
Report generation
yes
yes
yes
Server administration
yes via third parties (LizMap, QWC2, etc.)
web + API REST
web + API REST
GIS project Layer/symbology edition
complete via dedicated GUI
simple via web interface
complete via dedicated GUI
What are the OGC specification versions implemented in QGIS server compared to other web mapping servers? (2021/01/01)
OGC standards
QGIS Server
GeoServer
ArcGIS Server
WMS (Web Map Service)
1.3.0 - 1.1.1
1.3.0 - 1.1.1
1.3.0 - 1.1.1
WFS (Web Feature Service)
1.1.0 - 1.0.0
2.0.0 - 1.0.0
2.0.0 - 1.0.0
OAPIF (aka WFS3)
1.0.0
no
no
WMTS (Web Map Tile Service)
1.0.0
1.0.0
1.0.0
WCS (Web Coverage Service)
1.0.0
2.0.1 - 1.0.0
2.0.1 - 1.0.0
WPS (Web Processing Service)
no
1.0.0
1.0.0
CSW (Catalogue Service for the Web)
no
2.0.2
no
SLD (Styled Layer Descriptor)
yes
yes
yes
What is a tile cache?
Maps are often static. As most mapping clients render WMS (Web Map Service) data every time they are queried, this can result in unnecessary processing and increased wait times.
The tile cache optimizes this experience by saving (caching) map images, or tiles, as they are requested, in effect acting as a proxy between client (such as OpenLayers or Google Maps) and server (any WMS-compliant server). As new maps and tiles are requested, QGIS server intercepts these calls and returns pre-rendered tiles if stored, or calls the QGIs engine to render new tiles as necessary. Thus, once tiles are stored, the speed of map rendering increases by many times, creating a much improved user experience.
What is PostgreSQL?
PostgreSQL is a powerful, open source object-relational database companion for QGIS.
What is PostGIS?
PostGIS is a spatial database extender for PostgreSQL object-relational database. It adds support for geographic objects allowing location queries to be run in SQL.
To be continued...