Does anyone know if there is some kind of documentation on which database types that you can connect to in QGIS? I would also like to know if:
Can I use the databes for read only or read & write.
All database connections support read&write access (except for the Personal Geodatabase which is read-only via OGR).
The OGR Simple Features Library is a C++ open source library (and commandline tools) providing read (and sometimes write) access to a variety of vector file formats including ESRI Shapefiles, S-57, SDTS, PostGIS, Oracle Spatial, and Mapinfo mid/mif and TAB formats.
Here is a list of supported formats, including a number of different databases, that are supported by GDAL/OGR, and thus, QGIS. OGR Vector Formats.
Some of the databases include