<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_3786">Hi All,</div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_3790"><br class="" id="yui_3_16_0_1_1453140700579_4423"></div><div class="" dir="ltr" id="yiv4771610126yui_3_16_0_1_1452788258717_3808">I
am checking if there is a way to process quickly large datasets such as
census blocks in PostGIS and also by leveraging big data platform. I
have few questions in this regard.<br class="" id="yui_3_16_0_1_1453140700579_4426"></div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_3914" dir="ltr"><br class="" id="yui_3_16_0_1_1453140700579_4429"></div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_3895" dir="ltr"><div class="" id="yiv4771610126yui_3_16_0_1_1452885353580_7503" dir="ltr">1)
When I try intersect for sample census blocks with another polygon
layer, PostGIS 2.2(on Postgres 9.4) takes ~60 minutes (after optimizing
from <a class="" rel="nofollow" id="yiv4771610126yui_3_16_0_1_1452885353580_7501" target="_blank" href="http://postgis.net/2014/03/14/tip_intersection_faster/">http://postgis.net/2014/03/14/tip_intersection_faster/</a>
) while on ESRI ArcMap takes ~10 minutes. PostGIS layers already have
geospatial indices. Is there anyway to optimize this further?<br class="" id="yui_3_16_0_1_1453140700579_4434"></div></div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_4002" dir="ltr">2) What is an equivalent of ESRI Union in PostGIS? I didn't see any out of the box functions and any tips here are appreciated.</div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_4027" dir="ltr">3)
Is there anyway we can expedite these geoprocessing
tasks(union/intersect etc) using big data platform (Ex: hadoop)? Most
examples talk about analysis (contains etc) but not about geoprocessing
on geospatial data. Any input is appreciated.<br class="" id="yui_3_16_0_1_1453140700579_4438"></div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_4055" dir="ltr"><br class="" id="yui_3_16_0_1_1453140700579_4441"></div><div class="" id="yiv4771610126yui_3_16_0_1_1452788258717_4053" dir="ltr">Thanks,</div><div id="yui_3_16_0_1_1453140700579_4520" dir="ltr">Ravi.</div></div></body></html>