> I'd love to see on-disk bitmap indexes. I'm curious about what the performance ramifications of that would look like. I recently had to disable bitmap scans

> I'd love to see on-disk bitmap indexes. I'm curious about what the performance ramifications of that would look like. I recently had to disable bitmap scans in a data warehouse-type-thing I run because filesystem fragmentation was apparently misleading Postgres into thinking it would be cheaper than an index scan. The bitmap scan plan takes ~15 minutes to run cold, and the index scan takes ~20 seconds cold. (Really odd thing is that index scan takes ~1.5 seconds warm, versus ~0.4 seconds warm with the bitmap scan).