[postgis-users] raster2pgsql, _add_raster_constraint_extent fails with "array size exceeds the maximum allowed"

[Avernar]

I was importing a very large raster set and after a day it failed with
array size exceeds the maximum allowed when setting the extent
constraint.

I redid the import again by just doing the table create and then
adding the data and then doing the final bunch of sql statements
manually to avoid having the whole thing rollback again.

I first tried the fix discussed here
https://trac.osgeo.org/postgis/ticket/3501 and implemented here
https://trac.osgeo.org/postgis/changeset/15115 but that failed with
the array size error as well.  So I redid the constraints without the
extent one.

I would try ST_MemUnion but unfortunately that one is missing in my
installation.  I guess it's because it also handles 3D and the 3D
option is not compiled in by default on my platform.

So, what would a pl/pgsql script to do what MemUnion does, ie
accumulate one at a time, look like?

Also, what issues would not having an extent constrain have?