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Diffstat (limited to 'src/backend/utils/adt/date.c')
| -rw-r--r-- | src/backend/utils/adt/date.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c index 99448375ecf..2f6e19be372 100644 --- a/src/backend/utils/adt/date.c +++ b/src/backend/utils/adt/date.c @@ -447,6 +447,39 @@ date2timestamptz(DateADT dateVal) return result; } +/* + * date2timestamp_no_overflow + * + * This is chartered to produce a double value that is numerically + * equivalent to the corresponding Timestamp value, if the date is in the + * valid range of Timestamps, but in any case not throw an overflow error. + * We can do this since the numerical range of double is greater than + * that of non-erroneous timestamps. The results are currently only + * used for statistical estimation purposes. + */ +double +date2timestamp_no_overflow(DateADT dateVal) +{ + double result; + + if (DATE_IS_NOBEGIN(dateVal)) + result = -DBL_MAX; + else if (DATE_IS_NOEND(dateVal)) + result = DBL_MAX; + else + { +#ifdef HAVE_INT64_TIMESTAMP + /* date is days since 2000, timestamp is microseconds since same... */ + result = dateVal * (double) USECS_PER_DAY; +#else + /* date is days since 2000, timestamp is seconds since same... */ + result = dateVal * (double) SECS_PER_DAY; +#endif + } + + return result; +} + /* * Crosstype comparison functions for dates |