[postgis-users] Slow Query Times for Split Tiles

[elliott]

Should splitting raster files into tiles increase query performance?

I have a two 1201x1201 raster tiles that were loaded by the following 
scripts:

raster2pgsql.py -a -r N37E126.hgt -F N37E126 -t srtm3 -s 4326 
*-k1201x1201* > srtm.sql
psql -f srtm.sql TEST

raster2pgsql.py -a -r N37E127.hgt -F N37E127 -t srtm3 -s 4327 *-k50x50* 
 > srtm.sql
psql -f srtm.sql TEST

Querying these raster files appears to produce approximately the same 
timing results.  Should the 50x50 have better performance than the 
1201x1201?  Taking almost 3 minutes to query 10000 points seems to be 
very slow.

Number of Lat/Lon Pairs                  Time in secs for 
1201x1201           Time in secs for 50x50

1000                                                17 sec            
                                 20 sec
5000                                                85 sec            
                                 104 sec
10000                                              167 sec            
                               205 sec
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