🔥 On Sun, Jul 7, 2024, 7:44 AM Joel Jacobson <j...@compiler.org> wrote:
> On Sat, Jul 6, 2024, at 17:36, Dean Rasheed wrote: > > In the numeric width_bucket() code, we currently do the following: > .. > > Instead, this can be done more simply and efficiently, using division > > with truncation as follows: > .. > > > > Patch attached. I didn't bother with any new test cases, since there > > appears to be sufficient coverage already. > > > > As a quick performance/correctness test, I ran the following: > > > > SELECT setseed(0); > > CREATE TEMP TABLE t AS > > SELECT random(-4.000000, 8.000000) op, > > random(-4.100000, -2.000000) b1, > > random(6.000000, 8.100000) b2, > > random(1, 15) c > > FROM generate_series(1, 10000000); > > > > SELECT hash_array(array_agg(width_bucket(op, b1, b2, c))) FROM t; > > -- Result not changed by patch > > Same hash_array on all my three machines: > > hash_array > ------------- > -1179801276 > (1 row) > > > SELECT sum(width_bucket(op, b1, b2, c)) FROM t; > > Time: 3658.962 ms (00:03.659) -- HEAD > > Time: 3089.946 ms (00:03.090) -- with patch > > Significant improvement on all my three machines: > > /* > * Apple M3 Max > */ > > Time: 2255.154 ms (00:02.255) -- HEAD > Time: 1830.985 ms (00:01.831) > Time: 1826.190 ms (00:01.826) > Time: 1831.020 ms (00:01.831) > Time: 1832.934 ms (00:01.833) > Time: 1843.061 ms (00:01.843) > > Time: 1957.062 ms (00:01.957) -- simplify-width_bucket_numeric.patch > Time: 1545.121 ms (00:01.545) > Time: 1541.621 ms (00:01.542) > Time: 1536.388 ms (00:01.536) > Time: 1538.721 ms (00:01.539) > Time: 1592.384 ms (00:01.592) > > /* > * Intel Core i9-14900K > */ > > Time: 2541.959 ms (00:02.542) -- HEAD > Time: 2534.803 ms (00:02.535) > Time: 2532.343 ms (00:02.532) > Time: 2529.408 ms (00:02.529) > Time: 2528.600 ms (00:02.529) > > Time: 2107.901 ms (00:02.108) -- simplify-width_bucket_numeric.patch > Time: 2095.413 ms (00:02.095) > Time: 2093.985 ms (00:02.094) > Time: 2093.910 ms (00:02.094) > Time: 2094.935 ms (00:02.095) > > /* > * AMD Ryzen 9 7950X3D > */ > > > Time: 2226.498 ms (00:02.226) -- HEAD > Time: 2238.083 ms (00:02.238) > Time: 2239.075 ms (00:02.239) > Time: 2238.488 ms (00:02.238) > Time: 2238.166 ms (00:02.238) > > Time: 1853.382 ms (00:01.853) -- simplify-width_bucket_numeric.patch > Time: 1842.630 ms (00:01.843) > Time: 1828.309 ms (00:01.828) > Time: 1844.654 ms (00:01.845) > Time: 1828.520 ms (00:01.829) > > Regards, > Joel > > >
