diff options
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
| -rw-r--r-- | src/backend/utils/adt/timestamp.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 77202c8308e..4086a803dd7 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.22 2000/02/16 17:24:48 thomas Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/adt/timestamp.c,v 1.23 2000/03/14 23:06:37 thomas Exp $ * *------------------------------------------------------------------------- */ @@ -952,6 +952,32 @@ interval_cmp(Interval *interval1, Interval *interval2) return (span1 < span2) ? -1 : (span1 > span2) ? 1 : 0; } /* interval_cmp() */ +/* overlaps_timestamp() + * Implements the SQL92 OVERLAPS operator. + * Algorithm from Date and Darwen, 1997 + */ +bool +overlaps_timestamp(Timestamp *ts1, Timestamp *te1, Timestamp *ts2, Timestamp *te2) +{ + /* Make sure we have ordered pairs... */ + if (timestamp_gt(ts1, te1)) + { + Timestamp *tt = ts1; + ts1 = te1; + te1 = tt; + } + if (timestamp_gt(ts2, te2)) + { + Timestamp *tt = ts2; + ts2 = te2; + te2 = tt; + } + + return ((timestamp_gt(ts1, ts2) && (timestamp_lt(ts1, te2) || timestamp_lt(te1, te2))) + || (timestamp_gt(ts2, ts1) && (timestamp_lt(ts2, te1) || timestamp_lt(te2, te1))) + || timestamp_eq(ts1, ts2)); +} /* overlaps_timestamp() */ + /*---------------------------------------------------------- * "Arithmetic" operators on date/times. |