Otherwise, I was wondering if storing a bitmap of the keys used would be useful. Probably not.

No, you don't need DB_SET_RANGE. You get the cursor on the key you want with DB_GET and then keep calling DB_NEXT until you're done.

It sounds as though I can't do much better than my current solution and still obtain good performance. One thing that I can do to clean things up is use a Perl iterator.

Perhaps I can set this up to include a few parameters and hooks to define the format of the query string. This would yield the generic interface that I'm looking for, and perhaps would be worth releasing as a module.

The Bowtie remark was interesting; I'm well-acquainted with that relatively obscure package (as well as the equally obscure Dynamite), but don't think that the very cool and underutilized Burrows-Wheeler transform is applicable here.

Thanks again to all ...

My keys (to date) are usually floating point numbers which I format like %012.7f since these numbers will never exceed 9999.

Do you need 7 decimal places of accuracy? If your application could get by with 6, you could multiply your floats by 1e6 and store them as integers--which would probably reduce space and speed things up a lot whatever DB you use.

---

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

"Too many [] have been sedated by an oppressive environment of political correctness and risk aversion."

Yes, I do need all those decimal places sometimes. Using integers is a nice idea, though.