diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 000489d..47219bb 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -7358,12 +7358,9 @@ SELECT EXTRACT(EPOCH FROM INTERVAL '5 days 3 hours');
stamp:
-SELECT TIMESTAMP WITH TIME ZONE 'epoch' + 982384720.12 * INTERVAL '1 second';
+SELECT to_timestamp(982384720.12);
+Result: 2001-02-17 04:38:40.12+00
-
- (The to_timestamp function encapsulates the above
- conversion.)
-
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 3f013e3..9dad256 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -476,6 +476,74 @@ timestamptz_in(PG_FUNCTION_ARGS)
PG_RETURN_TIMESTAMPTZ(result);
}
+/* to_timestamp(double precision)
+ * Convert UNIX epoch to timestamptz.
+ */
+Datum
+unixtime_timestamptz(PG_FUNCTION_ARGS)
+{
+ float8 seconds = PG_GETARG_FLOAT8(0);
+ TimestampTz result;
+
+ int is_inf = is_infinite(seconds);
+
+ static const float8 epoch_lbound = (float8)SECS_PER_DAY * -UNIX_EPOCH_JDATE;
+ static const float8 epoch_ubound = (float8)SECS_PER_DAY *
+ (TIMESTAMP_END_JULIAN - UNIX_EPOCH_JDATE);
+
+ if(isnan(seconds))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid value for UNIX epoch \"%f\"", seconds),
+ errhint("Valid units for this parameter are finite floats, \"Infinity\" and \"-Infinity\"")));
+
+ if (is_inf < 0)
+ TIMESTAMP_NOBEGIN(result);
+
+ else if (is_inf > 0)
+ TIMESTAMP_NOEND(result);
+
+ else
+ {
+ if (seconds < epoch_lbound)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("UNIX epoch out of range: \"%lf\"", seconds)));
+
+ if (seconds >= epoch_ubound)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("UNIX epoch out of range: \"%lf\"", seconds)));
+
+ /* Convert UNIX epoch to Postgres epoch */
+ seconds -= ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY);
+
+#ifdef HAVE_INT64_TIMESTAMP
+ /*
+ * Here should be just "result = seconds * USECS_PER_SEC;",
+ * but for big values it leads loosing precision.
+ * Do as many operations as possible as integers.
+ */
+ {
+ int64 seconds_int = (int64)seconds;
+ fsec_t msec = (seconds - seconds_int) * USECS_PER_SEC;
+
+ result = (seconds_int * USECS_PER_SEC) + msec;
+ }
+#else
+ result = seconds;
+#endif
+ /* final range check catches just-out-of-range timestamps */
+ if (!IS_VALID_TIMESTAMP(result))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("UNIX epoch out of range: \"%lf\"",
+ PG_GETARG_FLOAT8(0))));
+ }
+
+ PG_RETURN_TIMESTAMP(result);
+}
+
/*
* Try to parse a timezone specification, and return its timezone offset value
* if it's acceptable. Otherwise, an error is thrown.
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index ceb8129..d7b94e8 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -1202,7 +1202,7 @@ DATA(insert OID = 1154 ( timestamptz_lt PGNSP PGUID 12 1 0 0 0 f f f t t f i
DATA(insert OID = 1155 ( timestamptz_le PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "1184 1184" _null_ _null_ _null_ _null_ _null_ timestamp_le _null_ _null_ _null_ ));
DATA(insert OID = 1156 ( timestamptz_ge PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "1184 1184" _null_ _null_ _null_ _null_ _null_ timestamp_ge _null_ _null_ _null_ ));
DATA(insert OID = 1157 ( timestamptz_gt PGNSP PGUID 12 1 0 0 0 f f f t t f i s 2 0 16 "1184 1184" _null_ _null_ _null_ _null_ _null_ timestamp_gt _null_ _null_ _null_ ));
-DATA(insert OID = 1158 ( to_timestamp PGNSP PGUID 14 1 0 0 0 f f f f t f i s 1 0 1184 "701" _null_ _null_ _null_ _null_ _null_ "select (''epoch''::pg_catalog.timestamptz + $1 * ''1 second''::pg_catalog.interval)" _null_ _null_ _null_ ));
+DATA(insert OID = 1158 ( to_timestamp PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 1184 "701" _null_ _null_ _null_ _null_ _null_ unixtime_timestamptz _null_ _null_ _null_ ));
DESCR("convert UNIX epoch to timestamptz");
DATA(insert OID = 3995 ( timestamp_zone_transform PGNSP PGUID 12 1 0 0 0 f f f f t f i s 1 0 2281 "2281" _null_ _null_ _null_ _null_ _null_ timestamp_zone_transform _null_ _null_ _null_ ));
DESCR("transform a time zone adjustment");
diff --git a/src/include/utils/timestamp.h b/src/include/utils/timestamp.h
index fbead3a..e18211d 100644
--- a/src/include/utils/timestamp.h
+++ b/src/include/utils/timestamp.h
@@ -124,6 +124,7 @@ extern Datum timestamp_cmp_timestamptz(PG_FUNCTION_ARGS);
extern Datum make_timestamp(PG_FUNCTION_ARGS);
extern Datum make_timestamptz(PG_FUNCTION_ARGS);
extern Datum make_timestamptz_at_timezone(PG_FUNCTION_ARGS);
+extern Datum unixtime_timestamptz(PG_FUNCTION_ARGS);
extern Datum timestamptz_eq_timestamp(PG_FUNCTION_ARGS);
extern Datum timestamptz_ne_timestamp(PG_FUNCTION_ARGS);
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index fffcaf4..e3aab6a 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -2256,6 +2256,54 @@ SELECT make_timestamptz(2007, 12, 9, 3, 0, 0, 'VET');
Sun Dec 09 07:30:00 2007 UTC
(1 row)
+SELECT to_timestamp( 0); -- 1970-01-01 00:00:00+00
+ to_timestamp
+------------------------------
+ Thu Jan 01 00:00:00 1970 UTC
+(1 row)
+
+SELECT to_timestamp( 946684800); -- 2000-01-01 00:00:00+00
+ to_timestamp
+------------------------------
+ Sat Jan 01 00:00:00 2000 UTC
+(1 row)
+
+SELECT to_timestamp(1262349296.7890123); -- 2010-01-01 12:34:56.789012+00
+ to_timestamp
+-------------------------------------
+ Fri Jan 01 12:34:56.789012 2010 UTC
+(1 row)
+
+-- edge cases
+SELECT to_timestamp(-1e20::float8); -- Error: UNIX epoch out of range
+ERROR: UNIX epoch out of range: "-100000000000000000000.000000"
+SELECT to_timestamp(-210866803200.0625); -- Error: UNIX epoch out of range
+ERROR: UNIX epoch out of range: "-210866803200.062500"
+SELECT to_timestamp(-210866803200); -- 4714-11-24 00:00:00+00 BC
+ to_timestamp
+---------------------------------
+ Mon Nov 24 00:00:00 4714 UTC BC
+(1 row)
+
+-- The upper boundary differs between integer and float timestamps, so check the biggest one
+SELECT to_timestamp(185331707078400::float8); -- Error: UNIX epoch out of range
+ERROR: UNIX epoch out of range: "185331707078400.000000"
+-- nonfinite values
+SELECT to_timestamp(' Infinity'::float);
+ to_timestamp
+--------------
+ infinity
+(1 row)
+
+SELECT to_timestamp('-Infinity'::float);
+ to_timestamp
+--------------
+ -infinity
+(1 row)
+
+SELECT to_timestamp('NaN'::float);
+ERROR: invalid value for UNIX epoch "nan"
+HINT: Valid units for this parameter are finite floats, "Infinity" and "-Infinity"
SET TimeZone to 'Europe/Moscow';
SELECT '2011-03-26 21:00:00 UTC'::timestamptz;
timestamptz
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 03dbc05..71c1657 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -386,6 +386,21 @@ SELECT '2007-12-09 04:00:00'::timestamp AT TIME ZONE 'VET';
SELECT make_timestamptz(2007, 12, 9, 2, 0, 0, 'VET');
SELECT make_timestamptz(2007, 12, 9, 3, 0, 0, 'VET');
+SELECT to_timestamp( 0); -- 1970-01-01 00:00:00+00
+SELECT to_timestamp( 946684800); -- 2000-01-01 00:00:00+00
+SELECT to_timestamp(1262349296.7890123); -- 2010-01-01 12:34:56.789012+00
+-- edge cases
+SELECT to_timestamp(-1e20::float8); -- Error: UNIX epoch out of range
+SELECT to_timestamp(-210866803200.0625); -- Error: UNIX epoch out of range
+SELECT to_timestamp(-210866803200); -- 4714-11-24 00:00:00+00 BC
+-- The upper boundary differs between integer and float timestamps, so check the biggest one
+SELECT to_timestamp(185331707078400::float8); -- Error: UNIX epoch out of range
+-- nonfinite values
+SELECT to_timestamp(' Infinity'::float);
+SELECT to_timestamp('-Infinity'::float);
+SELECT to_timestamp('NaN'::float);
+
+
SET TimeZone to 'Europe/Moscow';
SELECT '2011-03-26 21:00:00 UTC'::timestamptz;