[watersco]

Why only 11 buckets? That seems like the bigger issue. Converting an O(n) lookup to O(n/10) seems silly. Why not have 1000 buckets and get two more orders of magnitude improvement in lookup performance.

Of course that will expose how bad the hash function really is. Saving a few cycles in the hash function and then chaining through 17k linked list entries doesn't make any sense.

[wiredfool]

Because it was a design decision from 20 years ago for small n hash tables. It's baked into the design of his object db files.

[jallmann]

To be fair, we don't know the number of objects -- most of these 125k accesses could be lookups. But then again, if the number of objects is that small, then a hashtable strikes me as overkill. Otherwise yes, he should notch it up to a reasonable load factor.

But there's no denying how atrocious the hash function is. To quote:

> first and last characters of the name of the object, adds them together and mods the result by the number of buckets, which is 11

I don't know much about the name representation, but I'm guessing it's human readable ASCII. Which means your keys are confined to a very narrow range, and they'll be distributed along the same lines as the language itself (English or whatever). That means collisions up the wazoo.