From f2a2bf66c87e14f07aefe23cbbe2f2d9edcd9734 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Tue, 19 Apr 2022 20:38:53 +0200 Subject: [PATCH] Fix extract epoch from interval calculation The new numeric code for extract epoch from interval accidentally truncated the DAYS_PER_YEAR value to an integer, leading to results that mismatched the floating-point interval_part calculations. The commit a2da77cdb4661826482ebf2ddba1f953bc74afe4 that introduced this actually contains the regression test change that this reverts. I suppose this was missed at the time. Reported-by: Joseph Koshakow Reviewed-by: Tom Lane Discussion: https://www.postgresql.org/message-id/flat/CAAvxfHd5n%3D13NYA2q_tUq%3D3%3DSuWU-CufmTf-Ozj%3DfrEgt7pXwQ%40mail.gmail.com --- src/backend/utils/adt/timestamp.c | 14 ++++++++++---- src/test/regress/expected/interval.out | 4 ++-- 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index da73796eac..552b631ba7 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -5308,10 +5308,16 @@ interval_part_common(PG_FUNCTION_ARGS, bool retnumeric) int64 secs_from_day_month; int64 val; - /* this always fits into int64 */ - secs_from_day_month = ((int64) DAYS_PER_YEAR * (interval->month / MONTHS_PER_YEAR) + - (int64) DAYS_PER_MONTH * (interval->month % MONTHS_PER_YEAR) + - interval->day) * SECS_PER_DAY; + /* + * To do this calculation in integer arithmetic even though + * DAYS_PER_YEAR is fractional, multiply everything by 4 and then + * divide by 4 again at the end. This relies on DAYS_PER_YEAR + * being a multiple of 0.25 and on SECS_PER_DAY being a multiple + * of 4. + */ + secs_from_day_month = ((int64) (4 * DAYS_PER_YEAR) * (interval->month / MONTHS_PER_YEAR) + + (int64) (4 * DAYS_PER_MONTH) * (interval->month % MONTHS_PER_YEAR) + + (int64) 4 * interval->day) * (SECS_PER_DAY / 4); /*--- * result = secs_from_day_month + interval->time / 1'000'000 diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out index 03f77c01dc..00885acd1d 100644 --- a/src/test/regress/expected/interval.out +++ b/src/test/regress/expected/interval.out @@ -1655,11 +1655,11 @@ SELECT f1, @ 1 min | 0 | 0.000 | 0.000000 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 60.000000 @ 5 hours | 0 | 0.000 | 0.000000 | 0 | 5 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 18000.000000 @ 10 days | 0 | 0.000 | 0.000000 | 0 | 0 | 10 | 0 | 1 | 0 | 0 | 0 | 0 | 864000.000000 - @ 34 years | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 0 | 1 | 34 | 3 | 0 | 0 | 1072224000.000000 + @ 34 years | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 0 | 1 | 34 | 3 | 0 | 0 | 1072958400.000000 @ 3 mons | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 3 | 2 | 0 | 0 | 0 | 0 | 7776000.000000 @ 14 secs ago | -14000000 | -14000.000 | -14.000000 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | -14.000000 @ 1 day 2 hours 3 mins 4 secs | 4000000 | 4000.000 | 4.000000 | 3 | 2 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 93784.000000 - @ 6 years | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 0 | 1 | 6 | 0 | 0 | 0 | 189216000.000000 + @ 6 years | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 0 | 1 | 6 | 0 | 0 | 0 | 189345600.000000 @ 5 mons | 0 | 0.000 | 0.000000 | 0 | 0 | 0 | 5 | 2 | 0 | 0 | 0 | 0 | 12960000.000000 @ 5 mons 12 hours | 0 | 0.000 | 0.000000 | 0 | 12 | 0 | 5 | 2 | 0 | 0 | 0 | 0 | 13003200.000000 (10 rows)