From 4341f7ff48004bef2fe9707f1a03236d0bd7c4e7 Mon Sep 17 00:00:00 2001 From: Stepan Neretin Date: Tue, 11 Jun 2024 12:42:03 +0700 Subject: [PATCH v42 12/12] Add benchmark comparing float8 sorting methods Introduce `bench_float8_sort` to compare qsort with `sort_float8_arr`. It generates random float8 arrays, times sorting, and calculates performance difference. --- contrib/bench_sort_improvements/bench.c | 70 +++++++++++++++++++ .../bench_sort_improvements--1.0.sql | 2 + 2 files changed, 72 insertions(+) diff --git a/contrib/bench_sort_improvements/bench.c b/contrib/bench_sort_improvements/bench.c index c0d4ec86e1..a4088783c6 100644 --- a/contrib/bench_sort_improvements/bench.c +++ b/contrib/bench_sort_improvements/bench.c @@ -10,11 +10,13 @@ PG_MODULE_MAGIC; Datum bench_int_sort(PG_FUNCTION_ARGS); Datum bench_int16_sort(PG_FUNCTION_ARGS); +Datum bench_float8_sort(PG_FUNCTION_ARGS); Datum bench_oid_sort(PG_FUNCTION_ARGS); PG_FUNCTION_INFO_V1(bench_oid_sort); PG_FUNCTION_INFO_V1(bench_int_sort); PG_FUNCTION_INFO_V1(bench_int16_sort); +PG_FUNCTION_INFO_V1(bench_float8_sort); Datum bench_oid_sort(PG_FUNCTION_ARGS) @@ -153,6 +155,74 @@ bench_int16_sort(PG_FUNCTION_ARGS) PG_RETURN_TEXT_P(cstring_to_text(result_message)); } +double inline rand_double() { + return (double)rand() / RAND_MAX; +} + +/* +stupid copy for tests +*/ +static int +compareDoubles(const void *a, const void *b) +{ + float8 x = *(float8 *) a; + float8 y = *(float8 *) b; + + if (x == y) + return 0; + return (x > y) ? 1 : -1; +} + +/* +stupid copy for tests +*/ +#define ST_SORT sort_float8_arr +#define ST_ELEMENT_TYPE float8 +#define ST_COMPARE(a, b) compareDoubles(a, b) +#define ST_SCOPE static +#define ST_DEFINE +#include + +Datum +bench_float8_sort(PG_FUNCTION_ARGS) +{ + int32 arr_size = PG_GETARG_INT32(0); + float8 *arr_first = (float8 *)palloc(arr_size * sizeof(float8)); + float8 *arr_second = (float8 *)palloc(arr_size * sizeof(float8)); + struct timespec start, end; + long time_spent_first; + long time_spent_second; + double percentage_difference = 0.0; + char *result_message; + + for (int i = 0; i < arr_size; i++) + { + arr_first[i] = rand_double(); + arr_second[i] = rand_double(); + } + + // Timing the first sort function + clock_gettime(CLOCK_MONOTONIC, &start); + qsort(arr_first, arr_size, sizeof(float8), compareDoubles); + clock_gettime(CLOCK_MONOTONIC, &end); + time_spent_first = (end.tv_sec - start.tv_sec) * 1000000000L + (end.tv_nsec - start.tv_nsec); + + // Timing the second sort function + clock_gettime(CLOCK_MONOTONIC, &start); + sort_float8_arr(arr_second, arr_size); + clock_gettime(CLOCK_MONOTONIC, &end); + time_spent_second = (end.tv_sec - start.tv_sec) * 1000000000L + (end.tv_nsec - start.tv_nsec); + + percentage_difference = ((double)(time_spent_first - time_spent_second) / time_spent_first) * 100.0; + + pfree(arr_first); + pfree(arr_second); + + result_message = psprintf("Time taken by usual sort: %ld ns, Time taken by optimized sort: %ld ns, Percentage difference: %.2f%%", + time_spent_first, time_spent_second, percentage_difference); + PG_RETURN_TEXT_P(cstring_to_text(result_message)); +} + void _PG_init() { diff --git a/contrib/bench_sort_improvements/bench_sort_improvements--1.0.sql b/contrib/bench_sort_improvements/bench_sort_improvements--1.0.sql index bff8a6ab59..5c51a5ef81 100644 --- a/contrib/bench_sort_improvements/bench_sort_improvements--1.0.sql +++ b/contrib/bench_sort_improvements/bench_sort_improvements--1.0.sql @@ -3,3 +3,5 @@ create function bench_oid_sort(integer) returns text AS 'MODULE_PATHNAME', 'benc create function bench_int_sort(integer) returns text AS 'MODULE_PATHNAME', 'bench_int_sort' LANGUAGE C; create function bench_int16_sort(integer) returns text AS 'MODULE_PATHNAME', 'bench_int16_sort' LANGUAGE C; + +create function bench_float8_sort(integer) returns text AS 'MODULE_PATHNAME', 'bench_float8_sort' LANGUAGE C; -- 2.34.1