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bio website blog.jordogskog.no
location Hedmark, Norway
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visits member for 3 years, 9 months
seen 33 mins ago

Jul
18
comment Growth of a PostGIS database for Social Media - Move to Cassandra?
@Jay Cummins, I agree that the question isn't about query design and indexing. But to buy more ram before tuning the query seems like starting in the wrong end. That is more the microsoft/esri way of doing things :-)
Jul
18
comment Growth of a PostGIS database for Social Media - Move to Cassandra?
@mikedotonline ok, but do you have a spatial index that is functional?
Jul
17
comment Growth of a PostGIS database for Social Media - Move to Cassandra?
BTW, you say that you do the selection spatially, but you are also talking about many indexed columns. Why do you have many indexed columns if you don't use them for the selection?
Jul
17
comment Growth of a PostGIS database for Social Media - Move to Cassandra?
Ok, but still. If you have a working spatial index on the geometries I cannot understand that it should take that long time. 350 mill records is not that much.
Jul
17
comment Growth of a PostGIS database for Social Media - Move to Cassandra?
Are you sure it is the selection that is slow and not just the output of all the data. I mean an index search on a integer field like postal codes on 350 mill rows shouldn't be that slow I think.
Jun
16
comment Is it best to use multipolygon or polygon features for large intersect operations?
ST_Split is not the right function here. It will just split the polygon. Use ST_Intersection to get the interesecting part.
Jun
12
comment Closest Point within a Polygon
How is your data stored. If it is in a database like postgis this is a quite simple task with sql.
May
20
comment Function for Selecting Points in a Polygon
@brichins no the postgresql operators will not work on postgis type but as you say PostGIS has it's own that in many cases mean the same. But not alwayas. The last operator in your link also change meaning between PostGIS 1.4 and 1.5 if I recall right to mean only bbox comparasion.
May
18
comment Function for Selecting Points in a Polygon
@brichins, No PostGIS types has nothing to do with the PosgreSQL types. I don't even think there is some simåle cast between them. You have to use the PostGIS types to use the PostGIS functions.
May
15
comment PostGis geometry name lookup failed for table
A column of type polygon that contains points? I do not understand from what you are trying to build geometries. But to build a PostGIS geometry you will need to use a geometry constructor function like ST_Point(x, y).
May
15
comment How do I get started with PostGis
The url of today is postgis.net/documentation instead
Mar
13
comment Select point with highest value within a buffer
This seams to be a work for a spatial database to do with sql.
Mar
12
comment using postgis function in pyqgis
You need a second parameter for the buffer function that tells what buffer you want.
Mar
7
comment spatial database vs spatial datastructure?
Yes, I think PostgreSQL is much faster. That is often the case :-)
Mar
7
comment spatial database vs spatial datastructure?
You don't need to do the bounding box comparassion manually. It is built into ST_Intersets.
Nov
20
comment How can I improve the performance and start-up time of arcgis 10.x?
If you have a bad connection to the license server that can make things very slow. Note that license servers is not needed with open source software :-)
Nov
11
comment ST_Intersection point of two 3D linestrings - how is the Z value calculated?
This will not give the right answer in all cases. example is the linestrings: LINESTRING(2 0 0, 2 6 50) and LINESTRING(0 3 0, 5 3 0)
Nov
5
comment How to get the nearest point on a linestring to a given point?
St_distance between the point and the line will give you the same answer. Why do you think that you have to do it this way?
Oct
29
comment PostGIS ST_Contains Function Error
Upper or lower case in function names doesn't matter in PostgreSQL
Oct
7
comment Shortest distance from point to line (big dataset)
Postgis should do it fast