If it is a relatively small number, you could read them into a hash.

If it's a big number, you could read them into a disk-based hash like BerkeleyDB. It's a lot slower than an in-memory hash, of course, but it would make the code pretty easy to write.

If it was me, though, I'd probably use a database.

In reply to Re^2: 15 billion row text file and row deletes - Best Practice? by friedo
in thread 15 billion row text file and row deletes - Best Practice? by awohld

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