Hei all :)
I have a table where it holds 2 Geometry type columns, this_geom, and last_geom. I will be using this table as a reference table where I will either pass thisgid or this_geom and would like all the other data extracted. However an EXPLAIN SELECT on a where this_geom = '01050000E0777D00000100000001020000C00300000067DA64CD31AA224154740E5BC4D6094 1B3BA7124724E564000000000000000002152377FC8A92241D43FC27DA3D50941B3BA7124724 E56400000000000000000D3C361E8A5A82241105C30638AD209410B44B0E305FB55400000000 000000000' Gave me : "Seq Scan on streets_relation (cost=0.00..4666.80 rows=45 width=758)" " Filter: (this_geom = '01050000E0777D00000100000001020000C00300000067DA64CD31AA224154740E5BC4D6094 1B3BA7124724E564000000000000000002152377FC8A92241D43FC27DA3D50941B3BA7124724 E56400000000000000000D3C361E8A5A82241105C30638AD209410B44B0E305FB55400000000 000000000'::geometry)" Why rows does not equal to 1 but to 45? Does a GiST index in groups of 45? Can it be minimised to less groups please? This is the CREATE Table SQL text used : -- Table: streets_relation -- DROP TABLE streets_relation; CREATE TABLE streets_relation ( last_geom geometry, x_last double precision, y_last double precision, z_last double precision, lastid integer NOT NULL, stseg bigint, lastname character varying(80), this_geom geometry, x_this double precision, y_this double precision, z_this double precision, x_new double precision, y_new double precision, z_new double precision, thisname character varying(80), thisgid integer NOT NULL, CONSTRAINT "Primarky Key GID" PRIMARY KEY (lastid, thisgid) ) WITHOUT OIDS; ALTER TABLE streets_relation OWNER TO yancho; -- Index: "This Geom" -- DROP INDEX "This Geom"; CREATE INDEX "This Geom" ON streets_relation USING gist (this_geom); When I did where thisgid = 10 this is the result I got : "Index Scan using "Primarky Key GID" on streets_relation (cost=0.00..284.19 rows=1 width=758)" " Index Cond: (thisgid = 10)" Any idea on what I can do to improve the performance please? Thanks and regards Matthew _____ I am using the free version of SPAMfighter for private users. It has removed 23646 spam emails to date. Paying users do not have this message in their emails. Try SPAMfighter <http://www.spamfighter.com/len> for free now!
_______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
