[postgis-users] precision limitations

[Paul Ramsey]

Violetta Kalathaki wrote:

> Is there any precision limitation when storing vector geometry in PostgreSQL/PostGIS??
> Furthermore do any changes occur in data quality?I have to make an evaluation of  
> PostgreSQL/PostGIS and I would really appreciate an answer.

Double precision.  Whether changes occur in data quality is a matter of 
interpretation.  The ugly canonical form (hexwkb) is specifically to 
avoid data precision drift during input/output procedures.  Probably 
PostGIS is better at testing for and enforcing quality than many spatial 
systems. Want to test for validity? Use IsValid(). Enforce validity? 
Make IsValid() a column constraint.

P

> 
> Thanks in advance
> Mairy
> 
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   Paul Ramsey
   Refractions Research
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   pramsey at refractions.net
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