<div dir="ltr">Hi,<div><br></div><div>Interesting... Converting the geometries to EPSG:3758 gives me full precision results... even too much precision in fact.</div><div><br></div><div>Am I hitting a possible bug?<br><br>create materialized view boundaries6 as<br>(<br>SELECT ST_Union(st_transform(geom,3857)) AS geom<br>FROM isolated_polygons<br>);</div><div><br></div><div>create materialized view poligonos as<br>(<br>SELECT (st_dump(st_polygonize(geom))).geom as geom<br>FROM boundaries6<br>);<br><br>Output example:<br><br>POLYGON ((-1884304.8181563204 3847387.217700834, -1884303.6301477952 3847390.2815198163, -1884301.3926260301 3847398.3850115254, -1884299.3588698322 3847410.0745247495, -1884297.6065138557 3847432.9725758657, -1884296.370352658 3847461.3124003927, -1884285.5676204616 3847490.5777932494, -1884284.7220942706 3847500.8949590772, -1884285.5877451708 3847511.209780088, -1884288.1313066888 3847521.1258629817, -1884292.255031176 3847530.2621367835, -1884304.5612327529 3847544.838597601, -1884320.6135112965 3847552.7077727388, -1884329.301438646 3847553.711864505, -1884356.7018600577 3847595.5444918745, -1884350.6091230644 3847597.7214655625, -1884348.8417112504 3847597.9233964435, -1884341.920268925 3847598.7141872644, -1884341.5547124646 3847598.6704397635, -1884162.206055107 3847732.7449807688, -1884157.330000988 3847741.342988697, -1884210.2855140327 3848065.4651809186, -1884211.0698977145 3848066.2197755766, -1884217.0682683294 3848071.990343949, -1884222.6487752784 3848079.961606272, -1884226.8892119355 3848089.3659096505, -1884230.1943484417 3848110.7830938566, -1884227.0298437525 3848129.5450243745, -1884222.9641946238 3848138.7184024854, -1884217.469721009 3848146.773560765, -1884209.495630356 3848157.0619211486, -1884202.4868359105 3848163.241048862, -1884194.5976475216 3848167.677591741, -1884186.1312422808 3848170.201053893, -1884177.412979387 3848170.714458845, -1884157.7120793909 3848163.686625789, -1884146.5982598332 3848153.4266241263, -1884099.6259874147 3848131.588206478, -1884085.2123215708 3848132.893416493, -1884074.8880534563 3848129.9745710627, -1884006.686567626 3848152.1387122166, -1883999.7713783819 3848162.432206334, -1883986.525370213 3848172.981480761, -1883968.1933179696 3848177.6538106035, -1883959.5126945307 3848176.5642115613, -1883940.3595967775 3848165.418067268, -1883925.5155310663 3848151.8882741183, -1883917.5729368732 3848139.8137890203, -1883857.381093363 3848111.5022320007, -1883836.6232274584 3848117.720000616, -1883815.6242172741 3848124.2012419687, -1883795.1043865664 3848130.8164017973, -1883773.7927185367 3848133.674364157, -1883773.4405336839 3848133.6625647387, -1883764.9307116808 3848131.354253732, -1883756.9635983726 3848127.118674705, -1883749.845365454 3848121.1186005473, -1883743.8495626273 3848113.5846132124, -1883739.2066052258 3848104.8062422355, -1883736.094919506 3848095.120837853, -1883734.6340857996 3848084.9006064767, -1883734.8802431289 3848074.538306728, -1883736.823931808 3848064.4321558326, -1883740.3904569661 3848054.9705263535, -1883751.7045506823 3848030.4666622537, -1883759.5307865026 3848009.899583877, -1883774.9301102725 3847990.7332227444, -1883788.9531276273 3847983.8276264044, -1883798.370475629 3847982.581636236, -1883803.3564696491 3847982.6305539324, -1883808.8254005057 3847983.9783169357, -1883811.9033591086 3847984.736848943, -1883944.2994730875 3847833.871629596, -1883942.3214133624 3847812.6865095636, -1883939.7310583459 3847788.9131205995, -1883937.3284565676 3847767.9910749495, -1883935.3974736354 3847750.7967956406, -1883936.2118704196 3847732.3826482696, -1883941.080774071 3847708.957261322, -1883948.428618156 3847684.8137834826, -1883956.7098723128 3847659.216029763, -1883962.7544886847 3847645.0159646464, -1883976.3805608859 3847622.0625812984, -1883976.4801818964 3847621.894767933, -1883982.9920693361 3847613.159092793, -1884002.4959315164 3847598.585505623, -1884021.9036816845 3847588.5777258603, -1884042.4003578553 3847579.661401065, -1884062.794237262 3847570.8390545677, -1884085.218038963 3847559.5058541186, -1884105.6873629335 3847548.8405457577, -1884146.3744489253 3847487.370838038, -1884148.8150594376 3847470.16256415, -1884155.6282139579 3847450.87717117, -1884165.1022426507 3847427.336416116, -1884175.1243341307 3847404.260394368, -1884181.7489672431 3847395.018372707, -1884181.9541160655 3847394.7979852944, -1884188.7488454045 3847388.825408952, -1884209.00655479 3847374.3355192025, -1884210.7233128822 3847373.107561073, -1884217.8542574504 3847368.986041094, -1884225.4877985476 3847366.4321310967, -1884246.3156752721 3847361.7921338347, -1884257.154692483 3847360.9777463954, -1884267.8373182372 3847363.3036133484, -1884281.340372469 3847368.32697293, -1884290.0586065683 3847372.833651344, -1884304.8181563204 3847387.217700834))<br>POLYGON ((-1876206.2855346825 3847836.356218301, -1876213.9517881759 3847837.111815559, -1876238.76490267 3847842.148596314, -1876246.4897721622 3847844.580692201, -1876270.5000708427 3847854.957112778, -1876294.5103695232 3847865.333542457, -1876318.5288631248 3847875.683740962, -1876342.5606370806 3847885.9898018865, -1876358.1067283235 3847892.6567703243, -1876377.0049311635 3847908.617574078, -1876384.191861699 3847922.941528678, -1876435.9263317827 3847958.821861747, -1876451.2924678891 3847957.834976292, -1876476.0020765157 3847961.8433128675, -1876500.7116851422 3847965.8516508057, -1876525.4212937716 3847969.859990095, -1876541.8531569052 3847973.5510454606, -1876549.7864771339 3847977.875103052, -1876556.8570223656 3847983.9541076478, -1876562.793075515 3847991.554449007, -1876567.3665173864 3848000.384052895, -1876570.4015931743 3848010.1036049207, -1876571.781666619 3848020.3395898687, -1876571.4537022691 3848030.6986454, -1876569.4303036134 3848040.782678613, -1876556.7620823071 3848062.906127123, -1876544.474504419 3848103.1186408913, -1876536.4705924124 3848088.8048734763, -1876526.8713291166 3848071.158459993, -1876513.8057426987 3848053.8755431217, -1876498.5251660557 3848038.6726656007, -1876479.0519202838 3848020.8695257055, -1876462.1476702257 3847995.346476615, -1876445.3014369362 3847977.2476997958, -1876437.1638362387 3847973.497051448, -1876428.566456088 3847971.703829692, -1876419.8396889826 3847971.9369461425, -1876411.3188996902 3847974.187442382, -1876398.8038840995 3847979.4380840464, -1876390.8282430447 3847983.6509141587, -1876383.697917834 3847989.6306343884, -1876377.686922866 3847997.1474499176, -1876373.026257304 3848005.91249636, -1876371.0260549276 3848012.0937245083, -1876368.6388035628 3848036.167851205, -1876372.618960253 3848051.7714296845, -1876375.7576613792 3848058.5229933336, -1876379.533245313 3848166.297470614, -1876369.775387625 3848183.5411413587, -1876357.0092722771 3848208.9273151984, -1876344.243156932 3848234.3135435423, -1876336.4445368669 3848251.803340319, -1876310.3890798 3848308.105480734, -1876292.8235339515 3848325.64827115, -1876275.2579881032 3848343.1910875947, -1876258.140322357 3848360.5178122423, -1876240.6753970124 3848378.435703825, -1876223.2104716708 3848396.353622561, -1876205.7455463263 3848414.271568451, -1876190.496380243 3848435.2357344097, -1876188.5041804744 3848441.382478181, -1876175.6802522782 3848446.7096233866, -1876153.964067868 3848454.2477547023, -1876145.262931562 3848453.4204791524, -1876124.7839309415 3848441.8290587896, -1876116.0862495338 3848430.4926588554, -1876073.6693214423 3848390.7739995327, -1876063.3791579525 3848387.2665754347, -1875996.553527071 3848384.2336162594, -1875987.4865948088 3848388.538587899, -1875966.1524373947 3848391.6581394975, -1875947.799369681 3848391.1893235887, -1875931.4822491563 3848383.680621366, -1875886.9208690752 3848396.831050444, -1875866.7302966597 3848401.7902388633, -1875849.3606788714 3848402.2474827934, -1875840.953470879 3848399.458762576, -1875822.184677481 3848382.688905822, -1875815.1690762078 3848367.2838811954, -1875769.1787144816 3848351.7157003637, -1875747.1809534468 3848350.936353597, -1875743.3813192244 3848349.7308892296, -1875735.5496224375 3848345.1528666974, -1875728.6204446587 3848338.8482701606, -1875722.8600703056 3848331.0593842687, -1875718.4898673305 3848322.085534141, -1875715.677780184 3848312.2715820787, -1875714.5318757985 3848301.9946743585, -1875719.8684248503 3848275.5555036473, -1875727.7916337482 3848262.76994325, -1875750.3362411975 3848222.2697083377, -1875754.7871294252 3848206.5161465644, -1875742.2692607127 3848103.4182770974, -1875735.1057798397 3848095.3251489033, -1875726.8881497092 3848078.742704152, -1875724.3570128784 3848058.398189097, -1875718.1938969397 3848009.3275126973, -1875706.8020045527 3847994.471745596, -1875700.7199507852 3847974.7066694116, -1875700.2843567806 3847964.3532587904, -1875701.5579493775 3847954.097874521, -1875704.4917851256 3847944.334624517, -1875708.9731183609 3847935.438703329, -1875714.8297339657 3847927.7519739107, -1875721.8365654838 3847921.569830351, -1875729.7243443066 3847917.1298464444, -1875738.1899475218 3847914.602646254, -1875760.8253876907 3847917.836251649, -1875779.1813012215 3847927.722407194, -1875839.6392382558 3847916.7080737525, -1875847.6645522898 3847902.902541498, -1875864.2551363274 3847889.4786811387, -1875872.677495195 3847886.784032957, -1875896.780289324 3847889.2852114723, -1875920.1179041544 3847895.707716113, -1875937.8505189705 3847903.4325572257, -1875957.5891486697 3847914.1431340575, -1875977.3277783687 3847924.8537205877, -1876054.1260391686 3847919.4538371777, -1876073.8054144348 3847904.839822452, -1876093.4847897037 3847890.2258257843, -1876116.2257573933 3847870.791218101, -1876130.4613346022 3847861.037598793, -1876154.8176802786 3847855.307186942, -1876178.2325191353 3847845.168524966, -1876198.624175414 3847837.178850613, -1876206.2855346825 3847836.356218301))<br>POLYGON ((-1876544.474504419 3848103.1186408913, -1876543.8326752747 3848105.2191006835, -1876546.7289264835 3848127.920085206, -1876545.5359284605 3848137.233395549, -1876542.564784783 3848146.9808798665, -1876538.0494765278 3848155.8526974116, -1876532.1635244589 3848163.5079068835, -1876511.5703764597 3848175.706514713, -1876497.9576754894 3848176.626671925, -1876448.8350632659 3848194.056099103, -1876425.3492611286 3848236.5173345227, -1876419.7925063348 3848255.6842517625, -1876408.3034239912 3848271.162037587, -1876392.7014745248 3848280.240130746, -1876355.8397513435 3848325.7032860224, -1876352.1625399927 3848341.9048215672, -1876338.9274128082 3848362.1980404467, -1876322.3367223463 3848371.7842661925, -1876295.3121583033 3848406.0858179284, -1876286.3166743552 3848428.9527952927, -1876279.2407616368 3848437.3597535645, -1876271.8631297487 3848442.900441352, -1876263.7170912437 3848446.625315366, -1876255.1156938097 3848448.391229029, -1876232.2128869023 3848442.867444207, -1876213.8676121181 3848430.846339705, -1876188.5041804744 3848441.382478181, -1876190.496380243 3848435.2357344097, -1876205.7455463263 3848414.271568451, -1876223.2104716708 3848396.353622561, -1876240.6753970124 3848378.435703825, -1876258.140322357 3848360.5178122423, -1876275.2579881032 3848343.1910875947, -1876292.8235339515 3848325.64827115, -1876310.3890798 3848308.105480734, -1876336.4445368669 3848251.803340319, -1876344.243156932 3848234.3135435423, -1876357.0092722771 3848208.9273151984, -1876369.775387625 3848183.5411413587, -1876379.533245313 3848166.297470614, -1876375.7576613792 3848058.5229933336, -1876372.618960253 3848051.7714296845, -1876368.6388035628 3848036.167851205, -1876371.0260549276 3848012.0937245083, -1876373.026257304 3848005.91249636, -1876377.686922866 3847997.1474499176, -1876383.697917834 3847989.6306343884, -1876390.8282430447 3847983.6509141587, -1876398.8038840995 3847979.4380840464, -1876411.3188996902 3847974.187442382, -1876419.8396889826 3847971.9369461425, -1876428.566456088 3847971.703829692, -1876437.1638362387 3847973.497051448, -1876445.3014369362 3847977.2476997958, -1876462.1476702257 3847995.346476615, -1876479.0519202838 3848020.8695257055, -1876498.5251660557 3848038.6726656007, -1876513.8057426987 3848053.8755431217, -1876526.8713291166 3848071.158459993, -1876536.4705924124 3848088.8048734763, -1876544.474504419 3848103.1186408913))<br>POLYGON ((-1876188.5041804744 3848441.382478181, -1876213.8676121181 3848430.846339705, -1876232.2128869023 3848442.867444207, -1876255.1156938097 3848448.391229029, -1876263.7170912437 3848446.625315366, -1876271.8631297487 3848442.900441352, -1876279.2407616368 3848437.3597535645, -1876286.3166743552 3848428.9527952927, -1876295.3121583033 3848406.0858179284, -1876322.3367223463 3848371.7842661925, -1876338.9274128082 3848362.1980404467, -1876352.1625399927 3848341.9048215672, -1876355.8397513435 3848325.7032860224, -1876392.7014745248 3848280.240130746, -1876408.3034239912 3848271.162037587, -1876419.7925063348 3848255.6842517625, -1876425.3492611286 3848236.5173345227, -1876448.8350632659 3848194.056099103, -1876497.9576754894 3848176.626671925, -1876511.5703764597 3848175.706514713, -1876532.1635244589 3848163.5079068835, -1876538.0494765278 3848155.8526974116, -1876542.564784783 3848146.9808798665, -1876545.5359284605 3848137.233395549, -1876546.7289264835 3848127.920085206, -1876543.8326752747 3848105.2191006835, -1876544.474504419 3848103.1186408913, -1876555.364968197 3848122.594562845, -1876613.1520997677 3848162.3675248004, -1876643.7440328614 3848164.0146221793, -1876663.6927700208 3848164.5011996846, -1876683.192810332 3848167.12801539, -1876694.3396283644 3848172.942206207, -1876729.222851098 3848184.6999077704, -1876752.1308707832 3848189.0236756955, -1876775.2079730928 3848194.8107520035, -1876798.5387789228 3848201.0402887687, -1876818.0078754043 3848207.757704202, -1876825.5168982225 3848213.0434713834, -1876832.0133303176 3848219.9674387504, -1876842.4662997134 3848244.3378965603, -1876843.2054359675 3848261.707224046, -1876861.2688388631 3848312.1439763256, -1876871.8038666635 3848328.5512987934, -1876875.150448244 3848340.4371598824, -1876876.0940030015 3848353.6814036234, -1876917.9312230255 3848439.868789222, -1876970.7508031656 3848459.9319257336, -1876979.40250072 3848458.555547057, -1876990.0006676659 3848459.8050995087, -1877008.4619106373 3848470.1297051855, -1877017.0955844864 3848480.5056134313, -1877021.477160249 3848489.4717585254, -1877024.301687109 3848499.280817776, -1877025.4606200766 3848509.5558361392, -1877024.909422015 3848519.9019511133, -1877022.669275147 3848529.921566969, -1877018.8262670683 3848539.2296341895, -1877003.2592212302 3848556.884851514, -1876985.3633999326 3848594.025260806, -1876984.2504019388 3848618.3515737974, -1876979.8689933338 3848630.673808795, -1876974.6526896537 3848638.986054786, -1876955.3251426958 3848657.1895378665, -1876935.583089114 3848679.1664741687, -1876927.8490822841 3848695.4257583003, -1876921.5969562072 3848702.660283, -1876902.5348853646 3848721.058174326, -1876883.9019792771 3848742.645870728, -1876875.3838462024 3848755.907305373, -1876868.424151412 3848762.1645327415, -1876860.5703416185 3848766.688968825, -1876838.0377610966 3848776.5621749186, -1876829.349730498 3848779.224651684, -1876804.5796488456 3848783.971908446, -1876780.5805599443 3848791.596718001, -1876756.9410378663 3848792.3356899554, -1876734.2644018286 3848790.4642326944, -1876700.3784324513 3848803.482909626, -1876682.0011088175 3848816.599862887, -1876659.4327815596 3848827.5909101143, -1876639.8917685184 3848833.594604695, -1876635.4473263393 3848834.676561093, -1876610.7716336164 3848839.142003935, -1876591.586251268 3848842.613892571, -1876582.8695489783 3848843.1634326293, -1876574.230066107 3848841.6827377453, -1876553.9240153476 3848828.052519444, -1876544.9651251037 3848813.196665439, -1876541.8119837304 3848802.7424316006, -1876540.8592023957 3848798.2993606455, -1876463.435636762 3848723.940778296, -1876454.556063145 3848721.752043542, -1876439.7054872836 3848713.513660915, -1876340.6009741211 3848712.0397475157, -1876336.9716249965 3848714.6697668843, -1876325.1425350858 3848722.0441130563, -1876309.358982446 3848728.9070836334, -1876289.1966581808 3848731.4656279325, -1876282.3878467309 3848730.430180864, -1876274.1122191094 3848727.132655977, -1876266.5372747388 3848721.981034509, -1876259.9541144758 3848715.1732926485, -1876254.6157254823 3848706.971050703, -1876241.4056594612 3848681.0851763617, -1876233.2071627886 3848671.207664653, -1876228.4184083748 3848661.9271781407, -1876225.3308779148 3848651.678906895, -1876225.8657088026 3848625.151777304, -1876232.4587040814 3848603.8166017733, -1876237.1606100549 3848593.5774464393, -1876210.762329093 3848506.44601509, -1876201.7365914446 3848499.3614434074, -1876189.2612409296 3848478.9384858515, -1876188.0137353514 3848475.60259037, -1876186.0950818309 3848465.489351611, -1876185.8745866169 3848455.1259033694, -1876187.3607232203 3848444.9105072804, -1876188.5041804744 3848441.382478181))<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Mar 27, 2020 at 4:08 PM Alexandre Neto <<a href="mailto:senhor.neto@gmail.com">senhor.neto@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi,<div><br></div><div>I finally got to test this situation a bit more. The culprit seems to be the Union process:</div><div><br></div><div>with this to get all rings from the polygons, and which return their linestrings in full precision:</div><div><br></div><div><font face="monospace">create materialized view isolated_polygons as (<br>select st_exteriorring((st_dumprings((st_dump(geom)).geom)).geom) as geom<br>from OUTPUTS_FINAIS.estabelecimentos_as_400<br>)<br></font></div><div><br></div><div>All these produced a reduced precision output:</div><div><br></div><div><font face="monospace">create materialized view boundaries as<br>(<br>SELECT ST_Union(geom) AS geom<br>FROM isolated_polygons<br>);</font><br></div><div><br></div><div><font face="monospace">create materialized view boundaries2 as<br>(<br>SELECT ST_UnaryUnion(st_collect(geom)) AS geom<br>FROM isolated_polygons<br>);</font><br></div><div><br></div><div><font face="monospace">create materialized view boundaries3 as<br>(<br>SELECT ST_MemUnion(geom) AS geom<br>FROM isolated_polygons<br>);</font><br></div><div><br></div><div>BTW, my data is in EPSG:4326</div><div><br></div><div>I am now trying to convert data to another EPSG, to see what happens.</div><div><br></div><div>Thanks,</div><div><br></div><div>Alexandre Neto</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Mar 17, 2020 at 4:19 PM Alexandre Neto <<a href="mailto:senhor.neto@gmail.com" target="_blank">senhor.neto@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">I will, thank you!</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Mar 17, 2020 at 4:10 PM Martin Davis <<a href="mailto:mtnclimb@gmail.com" target="_blank">mtnclimb@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">It seems odd that precision is being reduced that much. In order to isolate where it is happening, you should capture output from each stage of the CTE (which is easy to do, by just truncating the CTE after each query and doing a "SELECT * FROM cte_tbl" . Then post the results here if you need help analyzing them, and so we can investigate further.<div><br></div><div>Even better would be to provide the dataset which is causing the problem, to aid in sorting this out.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Mar 16, 2020 at 7:16 PM Alexandre Neto <<a href="mailto:senhor.neto@gmail.com" target="_blank">senhor.neto@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi,<div><br></div><div>I am running a Overlay analysis, and I am following what is proposed by Paul Ramsey in this article:</div><div><br></div><div><a href="http://blog.cleverelephant.ca/2019/07/postgis-overlays.html" target="_blank">http://blog.cleverelephant.ca/2019/07/postgis-overlays.html</a><br></div><div><br></div><div>I am using this query on PostgreSQL 10 and PostGIS </div><div><br></div><div>With isolated_polygons as <br>(<br>select st_exteriorring((st_dumprings((st_dump(geom)).geom)).geom) as geom<br>from OUTPUTS_FINAIS.estabelecimentos_as_400<br>)<br>, boundaries as (<br>SELECT st_union(geom) AS geom<br>FROM isolated_polygons<br>)<br>, poligonos as (<br>SELECT (st_dump(st_polygonize(geom))).geom as geom<br>FROM boundaries<br>)<br>, n_poligonos as (<br>SELECT row_number() over() as id, geom<br>FROM poligonos<br>)<br>SELECT <a href="http://p.id" target="_blank">p.id</a>, count(id) as n_sobreposicoes, p.geom::geometry(polygon,4326)<br>into temp.sobreposicoes_400m<br>FROM n_poligonos as p <br> join outputs_finais.estabelecimentos_as_400 as t <br> on st_contains(t.geom,st_pointonsurface(p.geom))<br>GROUP BY id, p.geom;<br></div><div><br></div><div>When I use this with a sample set of input multipolygons, The results are what we would expect, all the overlapping polygons split and the count of the number of overlapping polygons.</div><div><br></div><div>When I run it with the full set (around 4800 polygons)</div><div><br></div><div>The precison of the output polygons gets truncated and instead of detailed polygons I get a "pixelied" output:</div><div><br></div><div>POLYGON ((-8.99 39.42, -8.99 39.43, -8.98 39.43, -8.97 39.43, -8.97 39.42, -8.98 39.42, -8.99 39.42))<br>POLYGON ((-8.19 39.56, -8.2 39.56, -8.2 39.57, -8.19 39.57, -8.18 39.57, -8.19 39.56))<br>POLYGON ((-8.54 41.02, -8.55 41.02, -8.55 41.03, -8.54 41.03, -8.54 41.02))<br>POLYGON ((-8.39 40.17, -8.4 40.17, -8.4 40.18, -8.39 40.18, -8.39 40.17))<br>POLYGON ((-8.57 38.83, -8.58 38.83, -8.59 38.84, -8.58 38.84, -8.57 38.84, -8.57 38.83))<br></div><div><br></div><div>My gut feeling is that this is happening at the polygonize level, but I am not sure.</div><div><br></div><div>I have also tried to use st_node + st_collect getting the same kind of results</div><div><br></div><div>Any idea of what can this be?</div><div><br></div><div>Since not all polygons are overlapping each other, I wanted to try to separate the analysis by chunks, but I fail to see how can I union or collect only not disjoint line groups.</div><div><br></div><div>I am using</div><div><br></div><div>PostgreSQL 10.12 (Ubuntu 10.12-0ubuntu0.18.04.1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0, 64-bit<br></div><div><br></div><div>POSTGIS="2.5.3 r17699" [EXTENSION] PGSQL="100" GEOS="3.7.1-CAPI-1.11.1 27a5e771" PROJ="Rel. 4.9.3, 15 August 2016" GDAL="GDAL 2.2.3, released 2017/11/20" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.2.1" RASTER<br></div><div><br></div><div>Thanks,</div><div><br></div><div>Alexandre Neto</div><div><br></div><div><br></div></div>
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