Shawn Pearce <spearce@xxxxxxxxxxx> writes: > Has anyone studied the impact of converting the pack idx fanout table > from 256 entries to 65536 entries? > > Back of the envelope estimates for 3.1M objects in linux.git suggests > a 2^16 fanout table would decrease the number of binary search > iterations from ~14 to ~6. The increased table costs an extra 255 KiB > of disk. On a 70M idx file this is noise. > > I'm starting to wonder if increasing the fanout table once the object > count is above a certain threshold is a reasonable optimization for > larger repositories. Yeah, and I do not think we have to be worried too much about backward compatibility for .idx files, as they are local and can be regenerated if an older version cannot read it. I also wonder if we can generate a finer-grained fan-out table on the fly, perhaps lazily, without changing the on-disk format ;-) -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html