[postgis-users] Spatially ordering data

[Tim Keitt]

http://www.keittlab.org/

On Wed, Mar 1, 2017 at 5:28 AM, Jonathan Moules <
jonathan-lists at lightpear.com> wrote:

> Hi List,
> I've got a database of about 60 million spatial features that I need to
> run through a process.
>
> The process can't do all of them at once, so I want to get the data from
> postgis in spatial chunks of up to say 500,000 features per query.
>

Can you define "spatial chunks"? Its pretty hard to answer if this is not
precise.


>
> The data itself isn't evenly spatially distributed, so gridding won't work
> either, and I don't see any prospectively useful functions in the reference.
>
> Non-spatially this would be simple:
>
>     *SELECT * FROM my_table ORDER BY some_key ASC LIMIT 500000 OFFSET 0*
>
> Does anyone have any suggestions for how to spatially order data with
> PostGIS?
>

If you want to limit the number of rows, declare a cursor (look up in
postgres docs) with a maximum number of rows to return.

THK


>
> Thanks,
> Jonathan
>
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