Optimize PostGIS query, ST_Intersects - Raster and Geom

المشرف العام

Administrator
طاقم الإدارة
I am trying to run a spatial query between two tables. Table one (prism_ppt_monthly - see below for details) is monthly precipitation data. Table two (usgs_basin_boundary - see below for details) are polygons of hydrologic basin boundaries.

I would like to create a time series of the total precipitation for each basin. I have a query that will do that (see below for details), but for a single calculation it takes nearly 4.75 seconds. Considering I have 1440 months of precipitation data and nearly 40 basins, this query would take: 4.75 sec * 1440 * 40 = 77 hours.

Below is the info on the query and tables. I have spatial indexes on each table (gist) and have VACUUM ANALYZED each table. Any ideas on how I might be able to speed this thing up would be greatly appreciated!!!

QUERY:

EXPLAIN ANALYZESELECT filename,date_from,date_to,site_no,sqmi,(ST_SummaryStats(rast)).* FROM prism_ppt_monthly, usgs_basin_boundary WHERE ST_Intersects(rast,ST_Transform(geom,4269)) LIMIT 1; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------ Limit (cost=65964.53..66000.10 rows=1 width=81) (actual time=4764.969..4764.972 rows=1 loops=1) -> Nested Loop (cost=65964.53..66782.60 rows=23 width=81) (actual time=4764.963..4764.963 rows=1 loops=1) Join Filter: _st_intersects(st_transform(usgs_basin_boundary.geom, 4269), prism_ppt_monthly.rast, NULL::integer) -> Hash Semi Join (cost=65964.53..66610.73 rows=47 width=126256) (actual time=4587.961..4587.961 rows=1 loops=1) Hash Cond: ((usgs_basin_boundary.site_no)::text = df_flow.code) -> Seq Scan on usgs_basin_boundary (cost=0.00..639.09 rows=2509 width=126256) (actual time=0.007..1.279 rows=595 loops=1) -> Hash (cost=65963.94..65963.94 rows=47 width=9) (actual time=4585.313..4585.313 rows=47 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 2kB -> HashAggregate (cost=65963.00..65963.47 rows=47 width=9) (actual time=4585.126..4585.215 rows=47 loops=1) -> Seq Scan on df_flow (cost=0.00..63244.20 rows=1087520 width=9) (actual time=5.826..2367.593 rows=1087520 loops=1) -> Index Scan using prism_ppt_monthly_rast_gist on prism_ppt_monthly (cost=0.00..0.40 rows=1 width=64) (actual time=0.034..0.034 rows=1 loops=1) Index Cond: ((rast)::geometry && st_transform(usgs_basin_boundary.geom, 4269)) Total runtime: 4765.151 msTABLE 1:

\d+ prism_ppt_monthly Table "public.prism_ppt_monthly" Column | Type | Modifiers | Storage | Description -----------+---------+-----------------------------------------------------------------+----------+------------- rid | integer | not null default nextval('prism_ppt_monthly_rid_seq'::regclass) | plain | rast | raster | | extended | filename | text | | extended | date_from | date | | plain | date_to | date | | plain | Indexes: "prism_ppt_monthly_pkey" PRIMARY KEY, btree (rid) "prism_ppt_monthly_rast_gist" gist (st_convexhull(rast)) Check constraints: "enforce_height_rast" CHECK (st_height(rast) = 621) "enforce_max_extent_rast" CHECK (st_coveredby(st_convexhull(rast), '0103000020AD10000001000000050000005555555555415FC01E01000000F8484060A9AAAAAA9E50C01E01000000F8484060A9AAAAAA9E50C0F5FFFFFFFF0F38405555555555415FC0F5FFFFFFFF0F38405555555555415FC01E01000000F84840'::geometry)) "enforce_nodata_values_rast" CHECK (_raster_constraint_nodata_values(rast)::numeric(16,10)[] = '{-9999}'::numeric(16,10)[]) "enforce_num_bands_rast" CHECK (st_numbands(rast) = 1) "enforce_out_db_rast" CHECK (_raster_constraint_out_db(rast) = '{f}'::boolean[]) "enforce_pixel_types_rast" CHECK (_raster_constraint_pixel_types(rast) = '{32BF}'::text[]) "enforce_same_alignment_rast" CHECK (st_samealignment(rast, '0100000000365755555555A53F365755555555A5BF5555555555415FC01E01000000F8484000000000000000000000000000000000AD10000001000100'::raster)) "enforce_scalex_rast" CHECK (st_scalex(rast)::numeric(16,10) = 0.04166666666667::numeric(16,10)) "enforce_scaley_rast" CHECK (st_scaley(rast)::numeric(16,10) = (-0.04166666666667)::numeric(16,10)) "enforce_srid_rast" CHECK (st_srid(rast) = 4269) "enforce_width_rast" CHECK (st_width(rast) = 1405) Has OIDs: noTable 2:

\d+ usgs_basin_boundary Table "public.usgs_basin_boundary" Column | Type | Modifiers | Storage | Description ----------+-----------------------------+-------------------------------------------------------------------+----------+------------- gid | integer | not null default nextval('usgs_basin_boundary_gid_seq'::regclass) | plain | site_no | character varying(15) | | extended | sqmi | numeric | | main | abs_diff | numeric | | main | geom | geometry(MultiPolygon,5070) | | main | Indexes: "usgs_basin_boundary_pkey" PRIMARY KEY, btree (gid) "usgs_basin_boundary_shape_gist" gist (geom)Has OIDs: no

أكثر...
 
أعلى