There are lots of ways in which you can improve your code.

The first is to tell mysql to build indexes on the chrom and the start columns. The second is to use prepared statements and execute() as show in the DBI documentation and in this tutorial.

If you use the RaiseError option in DBI->connect, you can leave out the ||die and get much better error messages.

It actually stops in a wierd way, like if the actual count is 30, it will only print 3. How do I deal with this?

How does it "stop"? Does it hang? or does it terminate? What is the exit code? does it run out of memory or disk space?

Perl 6 - links to (nearly) everything that is Perl 6.

In reply to Re^3: Searching and Coutning using 2 files with multiple columns by moritz
in thread Searching and Coutning using 2 files with multiple columns by shart3

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