[GRASS-dev] [GRASS GIS] #2258: t.create creates DB always in the PERMANENT

[GRASS GIS]

#2258: t.create creates DB always in the PERMANENT
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 Reporter:  martinl      |       Owner:  grass-dev@…              
     Type:  defect       |      Status:  new                      
 Priority:  normal       |   Milestone:  7.0.0                    
Component:  Temporal     |     Version:  unspecified              
 Keywords:  t.register   |    Platform:  Unspecified              
      Cpu:  Unspecified  |  
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Comment(by huhabla):

 There is a reason why the temporal database is generated and used by
 default in the PERMANENT directory. This will assure that by default all
 maps from different mapsets are registered in the same temporal database.
 A single temporal database can handle maps from different mapsets, it is
 designed to handle maps from different mapsets. Consider the temporal
 database as a location specific, mapset independent storage of temporal
 information. The temporal framework makes sure that you can not modify
 space time datasets or time stamps of maps "located" in other mapsets.

 You can use t.connect to use a different temporal database (a path for
 sqlite, connection string for postgresql). Hence you can force that the
 current mapset will be used to store time stamped maps and space time
 datasets by running t.connect in the new mapset. Be aware that the
 connection information is stored mapset specific.

 However, using mapset specific temporal databases has the drawback that
 temporal information from other mapsets (STDS, time stamped maps) will not
 be available. The reason is that sqlite does not support the merging of
 different database files at runtime.

 About temporal database creation: Each temporal command checks if a
 temporal database exists, if there is no temporal database then a new one
 will be created using the default settings (PERMANENT mapset) or the
 mapset specific settings set by t.connect. Hence if you modify the
 database connection at runtime with t.connect, the new temporal database
 will be used, or created if not present, when a temporal command gets
 invoked (except t.connect).

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2258#comment:3>
GRASS GIS <http://grass.osgeo.org>