3 ms·

I’d assume that most queries are limited by memory / disk access time, so for many queries the savings will be marginal. But I imagine that it could make comple

I’d assume that most queries are limited by memory / disk access time, so for many queries the savings will be marginal. But I imagine that it could make complex aggregates a lot faster?

openasocket 8y ago
True, I guess you'd see the advantage most when there is a complex WHERE clause or some complex projections and aggregates. Also, looking here https://www.pgcon.org/2017/schedule/attachments/467_PGCon%202017-05-26%2015-00%20ISPRAS%20Dynamic%20Compilation%20of%20SQL%20Queries%20in%20PostgreSQL%20Using%20LLVM%20JIT.pdf https://www.pgcon.org/2017/schedule/attachments/467_PGCon%20... it seems they can JIT the process for creating an index, which has some modest improvements. I imagine there are plenty of things like that that could also benefit from compilation.
- anarazel 8y ago
  > t seems they can JIT the process for creating an index, which has some modest improvements We could, but currently don't yet. Not enough time / too short days...
anarazel 8y ago
> I’d assume that most queries are limited by memory / disk access time That's not true for all that many analytics statements actually. Good storage systems can deliver data quite fast, and in many cases the buffer cache can hide a lot of the access latency too. There's obviously issues with memory access latencies, but that's actually something that JIT compilation can hide with, because it increases the amount of work that can be done in the out-of-order window. Without JIT there's just too many instructions for that to hide all that memory access latencies.