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How coordinates are stored in a PostgreSQL/PostGIS database? If not adjusted manually, is it "infinite"? Or up to some digits(15?).

My question is the following: If I work in a PostGIS database with "infinite" precision how is saving a layer as a shapefile or a feature class, process it and then paste it back to the PostGIS database, is going to affect my topology checklist? (for example exactly same nodes in a line segment).

And what would you do if you were to move from PostGIS and back regarding the precision and tolerance of your layer?

closed as too broad by PolyGeo Jun 11 at 20:38

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    There isn't really any such thing as "infinite" coordinate precision. Shapefile and PostGIS use 64-bit IEEE floating-point representation. File geodatabase uses compressed integer as described in the Understanding Coordinate Management in the Geodatabase whitepaper (internally, though the coordinates are exposed in 64-bit float) Furthermore, any geometry processed via ArcGIS will also have the compressed integer geometry rules applied. You'd need to provide a more concrete data flow to determine topology impact. – Vince Jun 11 at 16:23
  • @Vince That reads like an excellent answer to the question... – Richard Law Jun 11 at 20:10
  • As per the Tour there should be only one question asked per question. – PolyGeo Jun 11 at 20:39