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[PATCH v1] Fix floating-point noise in pg_stat_us_to_ms() 1+ messages / 1 participants [nested] [flat]
* [PATCH v1] Fix floating-point noise in pg_stat_us_to_ms() @ 2026-06-29 06:31 Bertrand Drouvot <bertranddrouvot.pg@gmail.com> 0 siblings, 0 replies; 1+ messages in thread From: Bertrand Drouvot @ 2026-06-29 06:31 UTC (permalink / raw) Multiplying by 0.001 can produce trailing-digit noise in displayed values (for example 0.009000000000000001 instead of 0.009, should extra_float_digits not being set to 0) because 0.001 cannot be represented exactly in binary floating point. Use division by 1000.0 instead as it is the most common way to deal with such computation in the code tree. Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com> --- src/backend/utils/adt/pgstatfuncs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 100.0% src/backend/utils/adt/ diff --git a/src/backend/utils/adt/pgstatfuncs.c b/src/backend/utils/adt/pgstatfuncs.c index 6f9c9c72de5..1e5f8293b28 100644 --- a/src/backend/utils/adt/pgstatfuncs.c +++ b/src/backend/utils/adt/pgstatfuncs.c @@ -1457,7 +1457,7 @@ pgstat_get_io_time_index(IOOp io_op) static inline double pg_stat_us_to_ms(PgStat_Counter val_ms) { - return val_ms * (double) 0.001; + return (double) val_ms / 1000.0; } /* -- 2.34.1 --TXuqZKQhWXLuSKvO-- ^ permalink raw reply [nested|flat] 1+ messages in thread
only message in thread Thread overview: 1+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2026-06-29 06:31 [PATCH v1] Fix floating-point noise in pg_stat_us_to_ms() Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
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