Mar 27, 2025

I was just running some tests, after adding some good instrumentation to measure hit rates. The rates were much lower than I expected. Then I realized that I used the same hash function for buckets and filters (I had a TODO to change it). But even so was getting a significant search reduction. Was around 1% of inserts, up to 25% now as about half done. Still, with identical hash functions that's pretty good... Everything that lands in a bucket is re-filtered on that landing criteria - which are all identical. So basically it's only applying one filter out of the 16 possible. I'll fix it up and run again in the morning.