[postgis-tickets] [PostGIS] #4334: Can't upgrade with a view based on ST_AsMVTGeom

[PostGIS]

#4334: Can't upgrade with a view based on ST_AsMVTGeom
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  Reporter:  Algunenano             |      Owner:  strk
      Type:  defect                 |     Status:  new
  Priority:  high                   |  Milestone:  PostGIS 2.4.7
 Component:  build/upgrade/install  |    Version:  2.4.x
Resolution:                         |   Keywords:
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Comment (by strk):

 This is a known issue with functions that change signature over time.
 Whenever a function changes signature in a significant way our upgrade
 process _drops_ the old function because CREATE OR REPLACE cannot do
 everything (like changing parameter names or types or introducing
 optional parameters).

 To reduce this problem it is HIGHLY ADVISABLE that we _always_ keep
 around a function with the old signature, being just a wrapper to
 the old. I've tried to do this whenever possible, but not all devs
 have taken this into account, saying that some functions should really
 just not be relied upon for views and the such. Enforcing such
 behavior is NOT EASY at all, as it would imply having our testsuite
 create a view using each and every existing function right before an
 upgrade (does actually sound like a plan, if you want to start this).

 An alternative "solution" to the problem would be to temporarely
 drop views relying on some functions and re-create them afterwards.
 This would of course ONLY WORK if the new function has a compatible
 signature with the old one (ie: not when dropping parameters).

 I hope this was a good starting point for you to fix this
 long-standing robustness issue :)

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4334#comment:2>
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