[postgis-tickets] [PostGIS] #5176: no data check in raster2pgsql and also ST_BandIsNoData are slow

[PostGIS]

#5176: no data check in raster2pgsql and also ST_BandIsNoData are slow
---------------------+-----------------------------
  Reporter:  robe    |      Owner:  robe
      Type:  defect  |     Status:  new
  Priority:  medium  |  Milestone:  PostGIS Fund Me
 Component:  raster  |    Version:  master
Resolution:          |   Keywords:
---------------------+-----------------------------
Comment (by robe):

 For this particular file, it was like 95% no data and 5% data.  After
 retiling, the time for the whole process for this took about 41 minutes


 {{{
 # this took 40 minutes
 raster2pgsql -I -t 128x128 -Y 15000 -e file_retiled.tif t_128_128 >>
 test.sql

 # this took 75.56 s
 psql -f test.sql
 }}}


 I think going direct to PostgreSQL took about 25 minutes, but have to
 recheck

 {{{
 raster2pgsql -I -t 128x128 -Y 15000 -e file_retiled.tif t_128_128 | psql
 }}}

 So much of the slowness was just the tiff blocksize of Block=637200x1.  It
 never completed so I killed it after 48 hrs.

 Still would be nice to get the no data checking timing down a bit, but it
 does end up much faster doing the no data check than trying to load like
 30GB of useless no data data in this case.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5176#comment:2>
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