ST_EuclideanDistance() TEST

• Testing Environment
• Test 0: NULL raster; Empty raster Test
• Test 1: Small number of sources vs low resolution raster: (Source: 10 points, Raster: 10x10)
• Test 2: Small number of sources vs high resolution raster:(Source: 10 points, Raster: 300x300)
• Test 3: Large number of sources vs high resolution raster:(Source: 1000 points, Raster: 300x300)
• Test 4: Performance test
• Test 5: Scalability test

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Testing Environment:

CPU: Intel Pentium 4, 3.00GHz
RAM: 2.00G
OS: MS Windows XP Professional 2002 SP 3
PostgreSQL 9.1
PostGIS 2.1.0SVN

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Test 0

CREATE TABLE test_source_raster_0 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,0,0,1,1,0,0,4326) AS rast)foo;
CREATE TABLE test_source_geometry_0 AS SELECT generate_series(1,10) AS id,ST_RandomPoints(the_geom,10) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_source_raster_0)foo;
CREATE TABLE test_ref_raster_0 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,0,0,1,1,0,0,4326) AS rast)foo;

• 0-a: Test NULL Raster. Should be true.

  SELECT ST_EuclideanDistance(NULL,NULL,'public','test_source_geometry_0','the_geom',False) IS NULL FROM test_ref_raster_0;
  

• 0-b: Test Empty Raster. Should be true.

  SELECT ST_IsEmpty(ST_EuclideanDistance(0,10,0,0,1,1,0,0,4326,-999,'32BF','public','test_source_geometry_0','the_geom',False));
  

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Test 1

Small number of sources vs low resolution raster: (Source: 10 points, Raster: 10x10)

• 1-a: Source geometry within the extent of the desired raster:
  

  CREATE TABLE test_source_raster_1 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,0,0,1,1,0,0,4326) AS rast)foo;
  CREATE TABLE test_source_geometry_1 AS SELECT generate_series(1,10) AS id,ST_RandomPoints(the_geom,10) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_source_raster_1)foo;
  CREATE TABLE test_ref_raster_1 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,0,0,1,1,0,0,4326) AS rast)foo;
  

  • 1-a-i: Generate Euclidean Distance from a one-band reference raster
    • 1-a-i-1: Snap is True; Max distance NOT specified:

      CREATE TABLE test_eudist_1_a_i_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1','the_geom',True) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-a-i-2: Snap is True; Max distance is specified:

      CREATE TABLE test_eudist_1_a_i_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1','the_geom',True,4) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-a-i-3: Snap is False; Max distance NOT specified:

      CREATE TABLE test_eudist_1_a_i_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1','the_geom',False) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-a-i-4: Snap is False; Max distance is specified:

      CREATE TABLE test_eudist_1_a_i_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1','the_geom',False,4) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
  • 1-a-ii: Generate Euclidean Distance from a set of raster specifications:
    • 1-a-ii-1: Snap is True; Max distance NOT specified:

      CREATE TABLE test_eudist_1_a_ii_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1','the_geom',True) AS rast);
      

      result: same as test_eudist_1_a_i_1.gif
      
      
    • 1-a-ii-2: Snap is True; Max distance is specified:

      CREATE TABLE test_eudist_1_a_ii_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1','the_geom',True,4) AS rast);
      

      result: same as test_eudist_1_a_i_2.gif
      
      
    • 1-a-ii-3: Snap is False; Max distance NOT specified:

      CREATE TABLE test_eudist_1_a_ii_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1','the_geom',False) AS rast);
      

      result: same as test_eudist_1_a_i_3.gif
      
      
    • 1-a-ii-4: Snap is False; Max distance is specified:

      CREATE TABLE test_eudist_1_a_ii_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1','the_geom',False,4) AS rast);
      

      result: same as test_eudist_1_a_i_4.gif
      
      

• 1-b: Source geometry completely outside of the extent of the desired raster:

  CREATE TABLE test_source_raster_1_b AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,-10,-12,1,1,0,0,4326) AS rast)foo;
  CREATE TABLE test_source_geometry_1_b AS SELECT generate_series(1,10) AS id,ST_RandomPoints(the_geom,10) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_source_raster_1_b)foo;
  

  • 1-b-i: Generate Euclidean Distance from a one-band reference raster:
    • 1-b-i-1: Snap is True; Max distance NOT specified:

      CREATE TABLE test_eudist_1_b_i_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_b','the_geom',True) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-b-i-2: Snap is True; Max distance is specified:

      CREATE TABLE test_eudist_1_b_i_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_b','the_geom',True,15) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-b-i-3: Snap is False; Max distance NOT specified:

      CREATE TABLE test_eudist_1_b_i_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_b','the_geom',False) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
    • 1-b-i-4: Snap is False; Max distance is specified:

      CREATE TABLE test_eudist_1_b_i_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_b','the_geom',False,15) AS rast FROM test_ref_raster_1);
      

      result:
      
      
      
  • 1-b-ii: Generate Euclidean Distance from a set of raster specifications:
    • 1-b-ii-1: Snap is True; Max distance NOT specified:

      CREATE TABLE test_eudist_1_b_ii_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_b','the_geom',True) AS rast);
      

      result: same as test_eudist_1_b_i_1.gif[BR]]
      
    • 1-b-ii-2: Snap is True; Max distance is specified:

      CREATE TABLE test_eudist_1_b_ii_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_b','the_geom',True,15) AS rast);
      

      result: same as test_eudist_1_b_i_2.gif[BR]]
      
    • 1-b-ii-3: Snap is False; Max distance NOT specified:

      CREATE TABLE test_eudist_1_b_ii_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_b','the_geom',False) AS rast);
      

      result: same as test_eudist_1_b_i_3.gif[BR]]
      
    • 1-b-ii-4: Snap is False; Max distance is specified:

      CREATE TABLE test_eudist_1_b_ii_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_b','the_geom',False,15) AS rast);
      

      result: same as test_eudist_1_b_i_4.gif[BR]]
      

• 1-c: Source geometry partially outside of the extent of the desired raster:

  CREATE TABLE test_source_raster_1_c AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(10,10,-5,-2,1,1,0,0,4326) AS rast)foo;
  CREATE TABLE test_source_geometry_1_c AS SELECT generate_series(1,10) AS id,ST_RandomPoints(the_geom,10) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_source_raster_1_c)foo;
  

  • 1-c-i: Generate Euclidean Distance from a one-band reference raster:

    CREATE TABLE test_eudist_1_c_i_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_c','the_geom',True) AS rast FROM test_ref_raster_1);
    

    result:
    
    
    
  • 1-c-i-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_1_c_i_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_c','the_geom',True,6) AS rast FROM test_ref_raster_1);
    

    result:
    
    
    
  • 1-c-i-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_1_c_i_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_c','the_geom',False) AS rast FROM test_ref_raster_1);
    

    result:
    
    
    
  • 1-c-i-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_1_c_i_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_1_c','the_geom',False,6) AS rast FROM test_ref_raster_1);
    

    result:
    
    
    

• 1-c-ii: Generate Euclidean Distance from a set of raster specifications:
  • 1-c-ii-1: Snap is True; Max distance NOT specified:

    CREATE TABLE test_eudist_1_c_ii_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_c','the_geom',True) AS rast);
    

    result: same as test_eudist_1_c_i_1.gif[BR]]
    
  • 1-c-ii-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_1_c_ii_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_c','the_geom',True,6) AS rast);
    

    result: same as test_eudist_1_c_i_2.gif[BR]]
    
  • 1-c-ii-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_1_c_ii_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_c','the_geom',False) AS rast);
    

    result: same as test_eudist_1_c_i_3.gif[BR]]
    
  • 1-c-ii-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_1_c_ii_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(10,10,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_1_c','the_geom',False,6) AS rast);
    

    result: same as test_eudist_1_c_i_4.gif[BR]]
    

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NOTICE: Cases of source point geometries OUTSIDE of the extent of the desired raster will NOT be tested for the following tests

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Test 2

Small number of sources vs high resolution raster:(Source: 10 points, Raster: 300x300)

CREATE TABLE test_ref_raster_2 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(300,300,0,0,1,1,0,0,4326) AS rast)foo;
CREATE TABLE test_source_geometry_2 AS SELECT generate_series(1,10) AS id,ST_RandomPoints(the_geom,10) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_2)foo;
CREATE INDEX test_source_geometry_2_gist_idx ON test_source_geometry_2 USING GIST (the_geom);

• 2-a: Generate Euclidean Distance from a one-band reference raster
  • 2-a-1: Snap is True; Max distance NOT specified:

    CREATE TABLE test_eudist_2_a_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_2','the_geom',True) AS rast FROM test_ref_raster_2);
    

    result:
    
    
    
  • 2-a-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_2_a_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_2','the_geom',True,125) AS rast FROM test_ref_raster_2);
    

    result:
    
    
    
  • 2-a-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_2_a_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_2','the_geom',False) AS rast FROM test_ref_raster_2);
    

    result:
    
    
    
  • 2-a-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_2_a_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_2','the_geom',False,) AS rast FROM test_ref_raster_2);
    

    result:
    
    
    
• 2-b: Generate Euclidean Distance from a set of raster specifications:
  • 2-b-1: Snap is True; Max distance NOT specified:

    CREATE TABLE test_eudist_2_b_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_2','the_geom',True) AS rast);
    

    result: same as test_eudist_2_a.gif
    
  • 2-b-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_2_b_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_2','the_geom',True,125) AS rast);
    

    result: same as test_eudist_2_a_2.gif
    
  • 2-b-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_2_b_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_2','the_geom',False) AS rast);
    

    result: same as test_eudist_2_a_3.gif
    
  • 2-b-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_2_b_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_2','the_geom',False,125) AS rast);
    

    result: same as test_eudist_2_a_4.gif
    

---

Test 3

Large number of sources vs high resolution raster:(Source: 1000 points, Raster: 300x300)

CREATE TABLE test_ref_raster_3 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(300,300,0,0,1,1,0,0,4326) AS rast)foo;
CREATE TABLE test_source_geometry_3 AS SELECT generate_series(1,1000) AS id,ST_RandomPoints(the_geom,1000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_3)foo;
CREATE INDEX test_source_geometry_3_gist_idx ON test_source_geometry_3 USING GIST (the_geom);

• 3-a: Generate Euclidean Distance from a one-band reference raster:
  • 3-a-1: Snap is True; Max distance NOT specified:

    CREATE TABLE test_eudist_3_a_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_3','the_geom',True) AS rast FROM test_ref_raster_3);
    

    result:
    
    
    
    result zoom in:
    
    
    
  • 3-a-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_3_a_2 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_3','the_geom',True,12) AS rast FROM test_ref_raster_3);
    

  • 3-a-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_3_a_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_3','the_geom',False) AS rast FROM test_ref_raster_3);
    

    result:
    
    
    
    result zoom in:
    
    
    
  • 3-a-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_3_a_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_3','the_geom',False,12) AS rast FROM test_ref_raster_3);
    

• 3-b: Generate Euclidean Distance from a set of raster specifications:
  • 3-b-1: Snap is True; Max distance NOT specified:

    CREATE TABLE test_eudist_3_b_1 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_3','the_geom',True) AS rast FROM test_ref_raster_3);
    

  • 3-b-2: Snap is True; Max distance is specified:

    CREATE TABLE test_eudist_3_b_2 AS (
    ..........SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_3','the_geom',True,12) AS rast FROM test_ref_raster_3);
    

  • 3-b-3: Snap is False; Max distance NOT specified:

    CREATE TABLE test_eudist_3_b_3 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_3','the_geom',False) AS rast FROM test_ref_raster_3);
    

  • 3-b-4: Snap is False; Max distance is specified:

    CREATE TABLE test_eudist_3_b_4 AS (SELECT 1 AS rid,ST_EuclideanDistance(300,300,0,0,1,1,0,0,4326,NULL,'32BF','public','test_source_geometry_3','the_geom',False,12) AS rast FROM test_ref_raster_3);
    

---

Test 4

Performance Test

Raster:	300x300
Source Points	Execution Time (ms)
100	122325
1,000	132139
5,000	126652
10,000	143764
20,000	120016
40,000	169386
80,000	164385
160,000	160800
320,000	204460
640,000	168992

CREATE TABLE test_ref_raster_4 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(300,300,0,0,1,1,0,0,4326) AS rast)foo;

• 4-a: Source: 100 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_a AS SELECT generate_series(1,100) AS id,ST_RandomPoints(the_geom,100) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_a_gist_idx ON test_source_geometry_4_a USING GIST (the_geom);
  CREATE TABLE test_eudist_4_a AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_a','the_geom',True) AS rast FROM test_ref_raster_4);
  

  122325 ms execution time.

result:

• 4-b: Source: 1,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_b AS SELECT generate_series(1,1000) AS id,ST_RandomPoints(the_geom,1000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_b_gist_idx ON test_source_geometry_4_b USING GIST (the_geom);
  CREATE TABLE test_eudist_4_b AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_b','the_geom',True) AS rast FROM test_ref_raster_4);
  

  132139 ms execution time.

result:

• 4-c: Source: 5,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_c AS SELECT generate_series(1,5000) AS id,ST_RandomPoints(the_geom,5000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_c_gist_idx ON test_source_geometry_4_c USING GIST (the_geom);
  CREATE TABLE test_eudist_4_c AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_c','the_geom',True) AS rast FROM test_ref_raster_4);
  

  126652 ms execution time.

result:

• 4-d: Source: 10,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_d AS SELECT generate_series(1,10000) AS id,ST_RandomPoints(the_geom,10000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_d_gist_idx ON test_source_geometry_4_d USING GIST (the_geom);
  CREATE TABLE test_eudist_4_d AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_d','the_geom',True) AS rast FROM test_ref_raster_4);
  

  143764 ms execution time.

result:

• 4-e: Source: 20,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_e AS SELECT generate_series(1,20000) AS id,ST_RandomPoints(the_geom,20000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_e_gist_idx ON test_source_geometry_4_e USING GIST (the_geom);
  CREATE TABLE test_eudist_4_e AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_e','the_geom',True) AS rast FROM test_ref_raster_4);
  

  120016 ms execution time.

result:

• 4-f: Source: 40,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_f AS SELECT generate_series(1,40000) AS id,ST_RandomPoints(the_geom,40000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_f_gist_idx ON test_source_geometry_4_f USING GIST (the_geom);
  CREATE TABLE test_eudist_4_f AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_f','the_geom',True) AS rast FROM test_ref_raster_4);
  

  169386 ms execution time.

result:

• 4-g: Source: 80,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_g AS SELECT generate_series(1,80000) AS id,ST_RandomPoints(the_geom,80000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_g_gist_idx ON test_source_geometry_4_g USING GIST (the_geom);
  CREATE TABLE test_eudist_4_g AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_g','the_geom',True) AS rast FROM test_ref_raster_4);
  

  164385 ms execution time.

result:

• 4-h: Source: 160,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_h AS SELECT generate_series(1,160000) AS id,ST_RandomPoints(the_geom,160000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_h_gist_idx ON test_source_geometry_4_h USING GIST (the_geom);
  CREATE TABLE test_eudist_4_h AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_h','the_geom',True) AS rast FROM test_ref_raster_4);
  

  160800 ms execution time.

result:

• 4-i: Source: 320,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_i AS SELECT generate_series(1,320000) AS id,ST_RandomPoints(the_geom,320000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_i_gist_idx ON test_source_geometry_4_i USING GIST (the_geom);
  CREATE TABLE test_eudist_4_i AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_i','the_geom',True) AS rast FROM test_ref_raster_4);
  

  204460 ms execution time.

result: too many source point, picture doesn't make too much sense.

• 4-j: Source: 640,000 points; Raster: 300x300

  CREATE TABLE test_source_geometry_4_j AS SELECT generate_series(1,640000) AS id,ST_RandomPoints(the_geom,640000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_4)foo;
  CREATE INDEX test_source_geometry_4_j_gist_idx ON test_source_geometry_4_j USING GIST (the_geom);
  CREATE TABLE test_eudist_4_j AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_4_j','the_geom',True) AS rast FROM test_ref_raster_4);
  

  168992 ms execution time.

result: too many source point, picture doesn't make too much sense.

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Test 5

Scalability test

Very large size source points vs very high resolution raster:

• 5-a: Source: 10,000 points; Raster: 1000x1000

  CREATE TABLE test_ref_raster_5 AS SELECT 1 AS rid,rast FROM (SELECT ST_MakeEmptyRaster(1000,1000,0,0,1,1,0,0,4326) AS rast)foo;
  CREATE TABLE test_source_geometry_5_a AS SELECT generate_series(1,10000) AS id,ST_RandomPoints(the_geom,10000) AS the_geom FROM (SELECT ST_SetSRID(ST_Extent(rast::geometry),4326) AS the_geom FROM test_ref_raster_5)foo;
  CREATE INDEX test_source_geometry_5_a_gist_idx ON test_source_geometry_5_a USING GIST (the_geom);
  CREATE TABLE test_eudist_5_a AS (SELECT 1 AS rid,ST_EuclideanDistance(rast,'32BF','public','test_source_geometry_5_a','the_geom',True) AS rast FROM test_ref_raster_5);
  

  1576434 ms execution time.

result: