I'd be surprised if you run out of memory, updating a field, even with a 50,000,000 row table.
Also, if you are working with real geospatial data such as Imagery or vector data, there are many applications that may be suited for these calculations. Spatialite is a Sqlite extension that has spatial indexes(rtree) and spatial functions such as buffer, intersect,etc Vander Clock Stephane wrote: > > i don't know but i quite sure not, because the cost to update all the > row in the table Hash will be much much (much) more expensive ... > and also this solution it's absolutely not multi thread :( > > On 12/23/2010 11:46 PM, stormtrooper wrote: >> would it run faster if you add two columns to the Hast table - randmax >> and >> randmin >> >> update Hash set randmax = max((<#randomnumber> % 255)-10,0) >> update Hash set randmin = min((<#randomnumber> % 255)+10,255) >> >> CREATE INDEX HASH_RMIN_IDX ON HASH (RANDMIN); >> CREATE INDEX HASH_RMAX_IDX ON HASH (RANDMAX); >> >> Select >> H1.ID >> from >> HASH1 H1 >> where >> x1_y1_min>= randmax and >> x1_y1_max<= randmin and >> x1_y2_min>= randmax and >> x1_y2_max<= randmin and >> x1_y3_min>= randmax and >> x1_y3_max<= randmin and >> x1_y4_min>= randmax and >> x1_y4_max<= randmin and >> x1_y5_min>= randmax and >> x1_y5_max<= randmin; >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- View this message in context: http://old.nabble.com/how-to-speed-up-this---tp30524605p30525283.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
