This issue has been confirmed on both GEOS and JTS. You have magic geometry that breaks the consistency between prepared and standard results.
https://github.com/libgeos/geos/pull/566 P. > On Feb 10, 2022, at 6:43 PM, Emily Gouge <ego...@refractions.net> wrote: > > Here you go. Thanks! > > > SELECT ST_AsHEXEWKB (geometry) FROM test.eflowpath WHERE id = > '889105be-5782-43f1-b50c-5a5825c83875' > > 01020000200912000007000000642F25DC75A24CC0E4DE5740FCB34840A7CEFE9B72A24CC09DA85B2CFBB34840B5519D0E64A24CC091FAA188FBB34840FA449E245DA24CC054C2137AFDB34840F4ACFFCE51A24CC09FEB562A03B448405328C1D144A24CC09A3DD00A0CB44840404C10C03CA24CC0EA07FE6910B44840 > > SELECT ST_AsHEXEWKB (geometry) FROM test.eflowpath WHERE id = > 'e5703673-a995-472e-b4b4-0280143eba0c' > > 0102000020091200000E00000004BE47A23CA24CC098A1F14410B448409871AEBC3FA24CC078341F2114B448400858AB764DA24CC09D0546031DB448406BFD3E2D50A24CC0BEDDEDD522B4484004824AA654A24CC02DC9A60128B44840EE377FB850A24CC0FA18BD642DB44840CCAF8B474EA24CC02CCCE78134B44840D7158E7B4EA24CC01D7C17A53AB44840ACFA01B452A24CC02688BA0F40B44840DB508C8752A24CC006CDF80846B44840A1F31ABB44A24CC0C891730756B44840009AF7EE45A24CC06B7649415CB448408C2ECAC749A24CC0CE57248161B44840A74302A150A24CC07DD00E1368B44840 > > On 2022-02-10 5:57 p.m., Paul Ramsey wrote: >>> On Feb 10, 2022, at 4:55 PM, Emily Gouge <ego...@refractions.net> wrote: >>> >>> I have a linear dataset on which I was building a query to find edges that >>> are “very close” but don’t touch. While working on this query I found some >>> unexpected results with the st_intersects and st_disjoint functions. As >>> outlined below, the query returned true for both st_instersects and >>> st_disjoint for a few geometries comparisons, but ONLY when a where clause >>> was used to filter the geometries spatially. When unique identifiers were >>> used to filter geometries only st_disjoint returns true. >>> >>> Versions: >>> Except where noted otherwise the results below reference testing on these >>> versions: >>> POSTGIS="3.2.0 3.2.0" [EXTENSION] PGSQL="140" GEOS="3.10.1-CAPI-1.16.0" >>> PROJ="7.2.1" LIBXML="2.9.9" LIBJSON="0.12" LIBPROTOBUF="1.2.1" WAGYU="0.5.0 >>> (Internal)" >>> PostgreSQL 14.1, compiled by Visual C++ build 1914, 64-bit >>> >>> When I run this query: >>> select a.id, b.id, >>> st_intersects(a.geometry, b.geometry), >>> st_intersects(b.geometry, a.geometry), >>> st_disjoint(a.geometry, b.geometry), >>> st_disjoint(b.geometry, a.geometry) >>> from test.eflowpath a, test.eflowpath b >>> where a.id != b.id >>> and st_dwithin(a.geometry, b.geometry, 0.00001) >>> and st_disjoint(a.geometry, b.geometry); >>> >>> PostGIS 3.2: 50 rows were returned, but there are three rows that return >>> true for both st_disjoint and st_intersects. Given the query this in itself >>> is a bit odd as you'd expect reciprocal results for the pairs of the >>> geometry (so at least 4 rows). >>> ------- >>> 889105be-5782-43f1-b50c-5a5825c83875 >>> e5703673-a995-472e-b4b4-0280143eba0c >>> true >>> true >>> true >>> true >>> ------- >>> 0d05aabb-9ff3-4d8f-b6c7-b2b44b0868c8 >>> 3a09b2af-5932-4e36-9e3e-d8109e5463fa >>> true >>> true >>> true >>> true >>> ------- >>> 3a09b2af-5932-4e36-9e3e-d8109e5463fa >>> 0d05aabb-9ff3-4d8f-b6c7-b2b44b0868c8 >>> true >>> true >>> true >>> true >>> ------- >>> ... >>> >>> Note: In PostGIS 3.1.2 50 rows were returned by only two rows returned true >>> for both disjoint and intersects. >>> >>> HOWEVER, >>> When I compare one pair of those edges specifically using the ids they are >>> only disjoint (which is the result I would expect to see) >>> >>> select a.id, b.id, >>> st_intersects(a.geometry, b.geometry), >>> st_intersects(b.geometry, a.geometry), >>> st_disjoint(a.geometry, b.geometry), >>> st_disjoint(b.geometry, a.geometry) >>> from test.eflowpath a, test.eflowpath b >>> where b.id = '889105be-5782-43f1-b50c-5a5825c83875' and a.id = >>> 'e5703673-a995-472e-b4b4-0280143eba0c' >>> >>> Results: >>> ------- >>> e5703673-a995-472e-b4b4-0280143eba0c >>> 889105be-5782-43f1-b50c-5a5825c83875 >>> false >>> false >>> true >>> true >>> ------- >>> >>> I thought perhaps this had something to do with the indexes so I removed >>> all geometry indexes from the table and re-ran the initial query. In >>> postgis 3.2 this returned the same results as the indexed query. >>> Note: In PostGIS 3.1.2 this also returned three rows with intersects and >>> disjoint true. As noted above with indexes in 3.1.2 only 2 rows were >>> returned where intersects and disjoint were true. >>> >>> Similar results occurred if st_dwithin from the where statement was >>> increased to 0.01. >>> >>> Test Data: When I made a table with only the edges in question all queries >>> returned expected results: st_intersects is false and st_disjoint is true. >>> As a result providing a small test case for this issue doesn’t seem >>> possible. But I am happy to provide all the data - there are 27,444 rows. >>> >>> While this isn’t a problem for me, I find it unexpected that the results >>> from st_intersects and st_disjoint of two geometries would be different >>> based on the where clause in the query (and the data in the table). >>> >>> Thoughts? >> The fact that a single test case returns one result, but results in a larger >> set returns another says to me that likely the issue in different code lines >> because of different cache behaviour. When you do the single test case you >> get a brute force intersects. When you do several in a batch, you get >> prepared geometry (at least, for the cases that happen after caching). >> If you can provide the HEXWKB of the two geometries that showed disagreement >> (where b.id = '889105be-5782-43f1-b50c-5a5825c83875' and a.id = >> 'e5703673-a995-472e-b4b4-0280143eba0c') we can set up a test case in GEOS >> that compares the normal and prepared geometry calls and see if that's the >> problem. >> P. >>> >>> Thanks, >>> Emily >>> _______________________________________________ >>> postgis-users mailing list >>> postgis-users@lists.osgeo.org >>> https://lists.osgeo.org/mailman/listinfo/postgis-users >> _______________________________________________ >> postgis-users mailing list >> postgis-users@lists.osgeo.org >> https://lists.osgeo.org/mailman/listinfo/postgis-users > _______________________________________________ > postgis-users mailing list > postgis-users@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/postgis-users