diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 0af01d9f10b2788a9fe377463fdf5bab3e01c598..4d2b88fafd3ee8b0c6e2a405a7d8052e6fb2dd96 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -7521,6 +7521,17 @@ SELECT EXTRACT(YEAR FROM TIMESTAMP '2001-02-16 20:38:40');
</variablelist>
</para>
+ <note>
+ <para>
+ When the input value is +/-Infinity, <function>extract</> returns
+ +/-Infinity for monotonically-increasing fields (<literal>epoch</>,
+ <literal>julian</>, <literal>year</>, <literal>isoyear</>,
+ <literal>decade</>, <literal>century</>, and <literal>millennium</>).
+ For other fields, NULL is returned. <productname>PostgreSQL</>
+ versions before 9.6 returned zero for all cases of infinite input.
+ </para>
+ </note>
+
<para>
The <function>extract</function> function is primarily intended
for computational processing. For formatting date/time values for
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 68710928718cb0573b12b7f03cb8e977097b4f71..1525d2a119202fe7cb45c2f4dbbfd90317bb56c2 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -4311,6 +4311,83 @@ date2isoyearday(int year, int mon, int mday)
return date2j(year, mon, mday) - isoweek2j(date2isoyear(year, mon, mday), 1) + 1;
}
+/*
+ * NonFiniteTimestampTzPart
+ *
+ * Used by timestamp_part and timestamptz_part when extracting from infinite
+ * timestamp[tz]. Returns +/-Infinity if that is the appropriate result,
+ * otherwise returns zero (which should be taken as meaning to return NULL).
+ *
+ * Errors thrown here for invalid units should exactly match those that
+ * would be thrown in the calling functions, else there will be unexpected
+ * discrepancies between finite- and infinite-input cases.
+ */
+static float8
+NonFiniteTimestampTzPart(int type, int unit, char *lowunits,
+ bool isNegative, bool isTz)
+{
+ if ((type != UNITS) && (type != RESERV))
+ {
+ if (isTz)
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("timestamp with time zone units \"%s\" not recognized",
+ lowunits)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("timestamp units \"%s\" not recognized",
+ lowunits)));
+ }
+
+ switch (unit)
+ {
+ /* Oscillating units */
+ case DTK_MICROSEC:
+ case DTK_MILLISEC:
+ case DTK_SECOND:
+ case DTK_MINUTE:
+ case DTK_HOUR:
+ case DTK_DAY:
+ case DTK_MONTH:
+ case DTK_QUARTER:
+ case DTK_WEEK:
+ case DTK_DOW:
+ case DTK_ISODOW:
+ case DTK_DOY:
+ case DTK_TZ:
+ case DTK_TZ_MINUTE:
+ case DTK_TZ_HOUR:
+ return 0.0;
+
+ /* Monotonically-increasing units */
+ case DTK_YEAR:
+ case DTK_DECADE:
+ case DTK_CENTURY:
+ case DTK_MILLENNIUM:
+ case DTK_JULIAN:
+ case DTK_ISOYEAR:
+ case DTK_EPOCH:
+ if (isNegative)
+ return -get_float8_infinity();
+ else
+ return get_float8_infinity();
+
+ default:
+ if (isTz)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("timestamp with time zone units \"%s\" not supported",
+ lowunits)));
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("timestamp units \"%s\" not supported",
+ lowunits)));
+ return 0.0; /* keep compiler quiet */
+ }
+}
+
/* timestamp_part()
* Extract specified field from timestamp.
*/
@@ -4327,12 +4404,6 @@ timestamp_part(PG_FUNCTION_ARGS)
struct pg_tm tt,
*tm = &tt;
- if (TIMESTAMP_NOT_FINITE(timestamp))
- {
- result = 0;
- PG_RETURN_FLOAT8(result);
- }
-
lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
VARSIZE_ANY_EXHDR(units),
false);
@@ -4341,6 +4412,17 @@ timestamp_part(PG_FUNCTION_ARGS)
if (type == UNKNOWN_FIELD)
type = DecodeSpecial(0, lowunits, &val);
+ if (TIMESTAMP_NOT_FINITE(timestamp))
+ {
+ result = NonFiniteTimestampTzPart(type, val, lowunits,
+ TIMESTAMP_IS_NOBEGIN(timestamp),
+ false);
+ if (result)
+ PG_RETURN_FLOAT8(result);
+ else
+ PG_RETURN_NULL();
+ }
+
if (type == UNITS)
{
if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
@@ -4538,12 +4620,6 @@ timestamptz_part(PG_FUNCTION_ARGS)
struct pg_tm tt,
*tm = &tt;
- if (TIMESTAMP_NOT_FINITE(timestamp))
- {
- result = 0;
- PG_RETURN_FLOAT8(result);
- }
-
lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
VARSIZE_ANY_EXHDR(units),
false);
@@ -4552,6 +4628,17 @@ timestamptz_part(PG_FUNCTION_ARGS)
if (type == UNKNOWN_FIELD)
type = DecodeSpecial(0, lowunits, &val);
+ if (TIMESTAMP_NOT_FINITE(timestamp))
+ {
+ result = NonFiniteTimestampTzPart(type, val, lowunits,
+ TIMESTAMP_IS_NOBEGIN(timestamp),
+ true);
+ if (result)
+ PG_RETURN_FLOAT8(result);
+ else
+ PG_RETURN_NULL();
+ }
+
if (type == UNITS)
{
if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, NULL) != 0)
diff --git a/src/test/regress/expected/date.out b/src/test/regress/expected/date.out
index 8923f6090abf9df3236b0f95b720ed5c26179445..56c55201f59defe4e1996bc3b617472b0213cdc6 100644
--- a/src/test/regress/expected/date.out
+++ b/src/test/regress/expected/date.out
@@ -899,6 +899,27 @@ SELECT date 'tomorrow' - date 'yesterday' AS "Two days";
--
-- test extract!
+--
+-- epoch
+--
+SELECT EXTRACT(EPOCH FROM DATE '1970-01-01'); -- 0
+ date_part
+-----------
+ 0
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMP '1970-01-01'); -- 0
+ date_part
+-----------
+ 0
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ '1970-01-01+00'); -- 0
+ date_part
+-----------
+ 0
+(1 row)
+
--
-- century
--
@@ -1184,6 +1205,227 @@ select isfinite('infinity'::date), isfinite('-infinity'::date), isfinite('today'
f | f | t
(1 row)
+--
+-- oscillating fields from non-finite date/timestamptz:
+--
+SELECT EXTRACT(HOUR FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM DATE '-infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM TIMESTAMP 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM TIMESTAMP '-infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM TIMESTAMPTZ 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM TIMESTAMPTZ '-infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+-- all possible fields
+SELECT EXTRACT(MICROSECONDS FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(MILLISECONDS FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(SECOND FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(MINUTE FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(HOUR FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(DAY FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(MONTH FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(QUARTER FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(WEEK FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(DOW FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(ISODOW FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(DOY FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(TIMEZONE FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(TIMEZONE_M FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+SELECT EXTRACT(TIMEZONE_H FROM DATE 'infinity'); -- NULL
+ date_part
+-----------
+
+(1 row)
+
+--
+-- monotonic fields from non-finite date/timestamptz:
+--
+SELECT EXTRACT(EPOCH FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM DATE '-infinity'); -- -Infinity
+ date_part
+-----------
+ -Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMP 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMP '-infinity'); -- -Infinity
+ date_part
+-----------
+ -Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ '-infinity'); -- -Infinity
+ date_part
+-----------
+ -Infinity
+(1 row)
+
+-- all possible fields
+SELECT EXTRACT(YEAR FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(DECADE FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(CENTURY FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(MILLENNIUM FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(JULIAN FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(ISOYEAR FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+SELECT EXTRACT(EPOCH FROM DATE 'infinity'); -- Infinity
+ date_part
+-----------
+ Infinity
+(1 row)
+
+--
+-- wrong fields from non-finite date:
+--
+SELECT EXTRACT(MICROSEC FROM DATE 'infinity'); -- ERROR: timestamp units "microsec" not recognized
+ERROR: timestamp units "microsec" not recognized
+CONTEXT: SQL function "date_part" statement 1
+SELECT EXTRACT(UNDEFINED FROM DATE 'infinity'); -- ERROR: timestamp units "undefined" not supported
+ERROR: timestamp units "undefined" not supported
+CONTEXT: SQL function "date_part" statement 1
-- test constructors
select make_date(2013, 7, 15);
make_date
diff --git a/src/test/regress/sql/date.sql b/src/test/regress/sql/date.sql
index a62e92a77ef6297356ce793d6a903f38161ee81b..e40b4c4856dc7205e57fbcfea48d7f5c116fb3e2 100644
--- a/src/test/regress/sql/date.sql
+++ b/src/test/regress/sql/date.sql
@@ -212,6 +212,12 @@ SELECT date 'tomorrow' - date 'yesterday' AS "Two days";
--
-- test extract!
--
+-- epoch
+--
+SELECT EXTRACT(EPOCH FROM DATE '1970-01-01'); -- 0
+SELECT EXTRACT(EPOCH FROM TIMESTAMP '1970-01-01'); -- 0
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ '1970-01-01+00'); -- 0
+--
-- century
--
SELECT EXTRACT(CENTURY FROM DATE '0101-12-31 BC'); -- -2
@@ -276,6 +282,53 @@ select 'infinity'::date, '-infinity'::date;
select 'infinity'::date > 'today'::date as t;
select '-infinity'::date < 'today'::date as t;
select isfinite('infinity'::date), isfinite('-infinity'::date), isfinite('today'::date);
+--
+-- oscillating fields from non-finite date/timestamptz:
+--
+SELECT EXTRACT(HOUR FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM DATE '-infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM TIMESTAMP 'infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM TIMESTAMP '-infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM TIMESTAMPTZ 'infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM TIMESTAMPTZ '-infinity'); -- NULL
+-- all possible fields
+SELECT EXTRACT(MICROSECONDS FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(MILLISECONDS FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(SECOND FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(MINUTE FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(HOUR FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(DAY FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(MONTH FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(QUARTER FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(WEEK FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(DOW FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(ISODOW FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(DOY FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(TIMEZONE FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(TIMEZONE_M FROM DATE 'infinity'); -- NULL
+SELECT EXTRACT(TIMEZONE_H FROM DATE 'infinity'); -- NULL
+--
+-- monotonic fields from non-finite date/timestamptz:
+--
+SELECT EXTRACT(EPOCH FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(EPOCH FROM DATE '-infinity'); -- -Infinity
+SELECT EXTRACT(EPOCH FROM TIMESTAMP 'infinity'); -- Infinity
+SELECT EXTRACT(EPOCH FROM TIMESTAMP '-infinity'); -- -Infinity
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ 'infinity'); -- Infinity
+SELECT EXTRACT(EPOCH FROM TIMESTAMPTZ '-infinity'); -- -Infinity
+-- all possible fields
+SELECT EXTRACT(YEAR FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(DECADE FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(CENTURY FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(MILLENNIUM FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(JULIAN FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(ISOYEAR FROM DATE 'infinity'); -- Infinity
+SELECT EXTRACT(EPOCH FROM DATE 'infinity'); -- Infinity
+--
+-- wrong fields from non-finite date:
+--
+SELECT EXTRACT(MICROSEC FROM DATE 'infinity'); -- ERROR: timestamp units "microsec" not recognized
+SELECT EXTRACT(UNDEFINED FROM DATE 'infinity'); -- ERROR: timestamp units "undefined" not supported
-- test constructors
select make_date(2013, 7, 15);