From 35fcb1b3d038a501f3f4c87c05630095abaaadab Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Fri, 15 May 2015 14:26:51 +0300 Subject: Allow GiST distance function to return merely a lower-bound. The distance function can now set *recheck = false, like index quals. The executor will then re-check the ORDER BY expressions, and use a queue to reorder the results on the fly. This makes it possible to do kNN-searches on polygons and circles, which don't store the exact value in the index, but just a bounding box. Alexander Korotkov and me --- src/backend/utils/adt/geo_ops.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'src/backend/utils/adt/geo_ops.c') diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c index 39a78552410..a3af08ad6b0 100644 --- a/src/backend/utils/adt/geo_ops.c +++ b/src/backend/utils/adt/geo_ops.c @@ -2657,6 +2657,18 @@ dist_ppoly(PG_FUNCTION_ARGS) PG_RETURN_FLOAT8(result); } +Datum +dist_polyp(PG_FUNCTION_ARGS) +{ + POLYGON *poly = PG_GETARG_POLYGON_P(0); + Point *point = PG_GETARG_POINT_P(1); + float8 result; + + result = dist_ppoly_internal(point, poly); + + PG_RETURN_FLOAT8(result); +} + static double dist_ppoly_internal(Point *pt, POLYGON *poly) { @@ -5112,6 +5124,21 @@ dist_pc(PG_FUNCTION_ARGS) PG_RETURN_FLOAT8(result); } +/* + * Distance from a circle to a point + */ +Datum +dist_cpoint(PG_FUNCTION_ARGS) +{ + CIRCLE *circle = PG_GETARG_CIRCLE_P(0); + Point *point = PG_GETARG_POINT_P(1); + float8 result; + + result = point_dt(point, &circle->center) - circle->radius; + if (result < 0) + result = 0; + PG_RETURN_FLOAT8(result); +} /* circle_center - returns the center point of the circle. */ -- cgit v1.2.3