*** src/backend/utils/adt/timestamp.c~	2009-10-30 14:45:40.000000000 +0000
--- src/backend/utils/adt/timestamp.c	2009-10-30 14:47:06.000000000 +0000
***************
*** 2105,2110 ****
--- 2105,2128 ----
  	PG_RETURN_INT32(interval_cmp_internal(interval1, interval2));
  }
  
+ Datum
+ interval_abs(PG_FUNCTION_ARGS)
+ {
+ 	Interval   *interval = PG_GETARG_INTERVAL_P(0);
+ 	Interval   *result, *intervalneg;
+ 
+ 	intervalneg = (Interval *) palloc(sizeof(Interval));
+ 	intervalneg->time = -interval->time;
+ 	intervalneg->day = -interval->day;
+ 	intervalneg->month = -interval->month;
+ 
+ 	if (interval_cmp_internal(interval, intervalneg) < 0)
+ 		result = intervalneg;
+ 	else
+ 		result = interval;
+ 	PG_RETURN_INTERVAL_P(result);
+ }
+ 
  /*
   * Hashing for intervals
   *