All, I am having some problems with a new database that I am trying to setup.
This database is a large file (about 8.7 GB without indexing). The problem I am having is that SELECT statements are extremely slow. The goal is to get the database file up and running for an embedded application (we have tons of storage space so the size is not a problem). Here is the schema layout: CREATE table Dted (dtedkey INTEGER PRIMARY KEY, dted_lat INTEGER, dted_lon INTEGER, dted_alt FLOAT); We lookup dted_alt based on dted_lat and dted_lon. Here is our SELECT statement: SELECT dted_alt FROM Dted WHERE (dted_lat=%d AND dted_lon=%d); The numbers fed to dted_lat and dted_lon are typically on the order of 370000 and -1110000. What can we do to speed up our SELECT statements? Minutes is unacceptable for our application. We were hoping we could run somewhere on the order of 500 queries per second and get valid results back. I am not an SQL expert, but I was reading about indexes that that it is best to have a specific index per SELECT. Since we only have one, this is the index I am creating now (it has been creating this index on my machine for the past 10 minutes now): CREATE INDEX idx_ll ON Dted(dted_lat,dted_lon); Is that a good index for my SELECT? Will it speed up the accesses? Any thoughts? Thanks! -- Jonathan _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
