I meant that indexing a column(s) will cause inserts into the table to take longer because the index structure needs to be updated as extra work. The goal would be to decrease retrieval times. I don't think that indexing will matter much in your case, but some performance tests would tell the story. Your performance numbers sound about right to me. Your code was running one transaction per insert. Making one transaction for 60,000 inserts saves a lot of time!!