== Purpose

This page is not a list of things that **will happen** it is a place to gather disruptive changes that might make sense for a PostGIS 3 release.

== Ideas

* Break out a `postgis_raster` extension with a `postgis` dependency, so raster support becomes optional.
* Require installation in a 'postgis' schema, always and for ever
* Yet another serialization, this time changing to use `external` storage type, and adding our own compression scheme for coordinates.
  * An uncompressed header, so header info can always be efficiently "sliced" and read, even for very large objects
  * A hash key for use in fast and small equality comparisons (for use in cached comparison code)
  * A compression format optimized for doubles
  * Other compression formats with other tradeoffs (?) like TWKB for higher ratio with precision loss
  * Implies indirection in coordinate access again: smaller, more efficient must be balanced against direct access to coordinates
* Move up to "modern" C and use whatever cool features we like from that
* Modern GEOS version requirement?
  * Some major GEOS surgery to allow memory management by palloc?
  * Some major GEOS surgery to build CoordinateSequence directly on top of PostGIS pointlists?