Links SQL is only as fast as your server setup. If you have mysql on a dual 2ghz athlon with 4GB RAM then I expect the number of queries Links SQL can execute will be significantly higher =)
If you have the GT libraries loaded into mod_perl (hence using Apache::DBI) then that's about as much as you can do regarding tuning Links SQL. The rest is down to the server.
If you have the GT libraries loaded into mod_perl (hence using Apache::DBI) then that's about as much as you can do regarding tuning Links SQL. The rest is down to the server.