[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):

 This isn't quite as bad of an issue as I thought.  The slowness of no data
 checking seemed to be attributed to the block size.

 After converting with:


 {{{
 gdal_translate -a_srs EPSG:4326 -co COMPRESS=LZW -co TILED=YES
 data/file.tif data/file_retiled.tif

 }}}

 which gives default of 256x256 blocks,


 {{{
 Upper Left  (-125.0000000,  49.0000000) (125d 0' 0.00"W, 49d 0' 0.00"N)
 Lower Left  (-125.0000000,  24.0000000) (125d 0' 0.00"W, 24d 0' 0.00"N)
 Upper Right ( -66.0000000,  49.0000000) ( 66d 0' 0.00"W, 49d 0' 0.00"N)
 Lower Right ( -66.0000000,  24.0000000) ( 66d 0' 0.00"W, 24d 0' 0.00"N)
 Center      ( -95.5000000,  36.5000000) ( 95d30' 0.00"W, 36d30' 0.00"N)
 Band 1 Block=256x256 Type=Byte, ColorInterp=Gray
   NoData Value=0
 }}}


 then the no data checking finished within about 20 minutes.  Still waiting
 for the load though.
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5176#comment:1>
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