On 12/03/2019 04:47, Peter Geoghegan wrote:
In conclusion: I think that this regression is a cost worth accepting. The regression in throughput is relatively small (2% - 3%), and the NEW_ORDER transaction seems to be the only problem (NEW_ORDER happens to be used for 45% of all transactions with TPC-C, and inserts into the largest index by far, without reading much). The patch overtakes master after a few hours anyway -- the patch will still win after about 6 hours, once the database gets big enough, despite all the contention. As I said, I think that we see a regression*because* the indexes are much smaller, not in spite of the fact that they're smaller. The TPC-C/BenchmarkSQL indexes never fail to be about 40% smaller than they are on master, no matter the details, even after many hours.
Yeah, that's fine. I'm curious, though, could you bloat the indexes back to the old size by setting the fillfactor?
- Heikki
