[postgis-users] Using st_intersects without a defined projection

2015-02-11 Thread Trang Nguyen
Hello, I have two tables with geometry columns defined as geometry(POINT), geometry(LINESTRING), and geometry(MULTIPOLYGON), passed in as a sequence of lon/lat coordinates. I don't have any projection defined on these tables, so I believe it's using the system SRID of 0. Would I get accurate re

Re: [postgis-users] Hardware requirements for a server

2015-02-11 Thread Mathieu Basille
Thanks to everyone who contributed to this thread, either on the PostGIS [1] or the PostgreSQL [2] mailing lists. I will try to summarize everything in this message, which I will actually post on both lists to give an update to everyone. I hope it can be useful for other people interested. Pleas

[postgis-users] st_intersects not working

2015-02-11 Thread Rhys A.D. Stewart
Greetings all, I am working on a set of data where I have noded linestrings. All linestrings have just two points and the nodes were derived from the endpoints. I've found one instance where st_intersects and st_equals return the incorrect value (AFAICT). == select

Re: [postgis-users] Hardware requirements for a server

2015-02-11 Thread Rémi Cura
Own setup : dell precision 2*6 cores, 20 go RAM, SSD for index, 7200 HDD for big tables. I do very different stuff with the server : - base for visualisation of classical vector table (Usually few users mostly reading.) - base for automatic road generation (topology + very very complex query) -

Re: [postgis-users] Question on optimizing slow geospatial query

2015-02-11 Thread Rémi Cura
Hey, for the following I make the hypothesis that 1. for you trip A->B should be separated from trip B->A. 2. od1.taz.geom are non overlaping polygon (ie your zone are non overlaping) 3. whatever startloc, endloc, there exist a zone overlapping it. Now you querry look like this --compute the o

Re: [postgis-users] Question on optimizing slow geospatial query

2015-02-11 Thread Trang Nguyen
Hi Birgit, Thanks very much. I'm not familiar with the "with" clause but will look into that. There are also indices on startts and z.uuid ( time range condition is ok, since these are timestamps and not days). I am also finding that a cause of slowness was due to the OR condition: ST_intersec

Re: [postgis-users] Question on optimizing slow geospatial query

2015-02-11 Thread Birgit Laggner
Hi Trang, I think, it could help to create btree indices on "startts" and "uuid", too, since you are using them in your where clause as a filter (a probably unnecessary question regarding your date filter: I would expect the result of "t.startts > '2015-01-16' and t.startts < '2015-01-17'" to