From e136d38967a863452762e1ee6e28d9ab40056adf Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Tue, 10 Oct 2023 13:28:46 +0900 Subject: [PATCH v5] Add support for AT LOCAL with timestamps When converting a timestamp to/from with/without time zone, the SQL Standard specifies an AT LOCAL variant of AT TIME ZONE which uses the session's time zone. Note: bump catalog version --- src/include/catalog/pg_proc.dat | 6 +++ src/backend/parser/gram.y | 7 +++ src/backend/utils/adt/ruleutils.c | 9 ++++ src/backend/utils/adt/timestamp.c | 20 ++++++++ src/test/regress/expected/timestamptz.out | 47 +++++++++++++++++ src/test/regress/sql/timestamptz.sql | 21 ++++++++ doc/src/sgml/func.sgml | 62 +++++++++++++++++++++-- 7 files changed, 169 insertions(+), 3 deletions(-) diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index f0b7b9cbd8..21645b63a4 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -2319,6 +2319,12 @@ { oid => '1159', descr => 'adjust timestamp to new time zone', proname => 'timezone', prorettype => 'timestamp', proargtypes => 'text timestamptz', prosrc => 'timestamptz_zone' }, +{ oid => '9159', descr => 'adjust timestamp to local time zone', + proname => 'timezone', prorettype => 'timestamp', + proargtypes => 'timestamptz', prosrc => 'timestamptz_at_local' }, +{ oid => '9160', descr => 'adjust timestamp to local time zone', + proname => 'timezone', prorettype => 'timestamptz', + proargtypes => 'timestamp', prosrc => 'timestamp_at_local' }, { oid => '1160', descr => 'I/O', proname => 'interval_in', provolatile => 's', prorettype => 'interval', diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index e56cbe77cb..50ed504e5a 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -14508,6 +14508,13 @@ a_expr: c_expr { $$ = $1; } COERCE_SQL_SYNTAX, @2); } + | a_expr AT LOCAL %prec AT + { + $$ = (Node *) makeFuncCall(SystemFuncName("timezone"), + list_make1($1), + COERCE_SQL_SYNTAX, + -1); + } /* * These operators must be called out explicitly in order to make use * of bison's automatic operator-precedence handling. All other diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 442205382e..9d1b0b13b1 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -10347,6 +10347,15 @@ get_func_sql_syntax(FuncExpr *expr, deparse_context *context) appendStringInfoChar(buf, ')'); return true; + case F_TIMEZONE_TIMESTAMP: + case F_TIMEZONE_TIMESTAMPTZ: + /* AT LOCAL */ + appendStringInfoChar(buf, '('); + get_rule_expr_paren((Node *) linitial(expr->args), context, false, + (Node *) expr); + appendStringInfoString(buf, " AT LOCAL)"); + return true; + case F_OVERLAPS_TIMESTAMPTZ_INTERVAL_TIMESTAMPTZ_INTERVAL: case F_OVERLAPS_TIMESTAMPTZ_INTERVAL_TIMESTAMPTZ_TIMESTAMPTZ: case F_OVERLAPS_TIMESTAMPTZ_TIMESTAMPTZ_TIMESTAMPTZ_INTERVAL: diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 0e50aaec5a..2378ad7269 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -5921,3 +5921,23 @@ generate_series_timestamptz_at_zone(PG_FUNCTION_ARGS) { return generate_series_timestamptz_internal(fcinfo); } + +/* timestamp_at_local() + * timestamptz_at_local() + * + * These are necessary to pass the sanity check in opr_sanity, which checks + * that all built-in functions that share the implementing C function take + * the same number of arguments, and the grammar for AT LOCAL needs an + * overloaded name to handle both types of timestamp. + */ +Datum +timestamp_at_local(PG_FUNCTION_ARGS) +{ + return timestamp_timestamptz(fcinfo); +} + +Datum +timestamptz_at_local(PG_FUNCTION_ARGS) +{ + return timestamptz_timestamp(fcinfo); +} diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out index 0dd2fe2c82..780de18cf9 100644 --- a/src/test/regress/expected/timestamptz.out +++ b/src/test/regress/expected/timestamptz.out @@ -3135,6 +3135,53 @@ SELECT '2014-10-25 23:00:00 UTC'::timestamptz AT TIME ZONE 'MSK'; Sun Oct 26 02:00:00 2014 (1 row) +-- +-- Test AT LOCAL +-- +BEGIN; +SET LOCAL TIME ZONE 'Europe/Paris'; +VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL); + column1 +-------------------------- + Sat Jul 08 01:38:00 1978 +(1 row) + +VALUES (TIMESTAMP '1978-07-07 19:38' AT LOCAL); + column1 +------------------------------- + Fri Jul 07 19:38:00 1978 CEST +(1 row) + +SET LOCAL TIME ZONE 'Australia/Sydney'; +VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL); + column1 +-------------------------- + Sat Jul 08 09:38:00 1978 +(1 row) + +VALUES (TIMESTAMP '1978-07-07 19:38' AT LOCAL); + column1 +------------------------------- + Fri Jul 07 19:38:00 1978 AEST +(1 row) + +RESET TIME ZONE; +CREATE VIEW local_time_zone AS + VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL, + timezone(CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE)), + TIMESTAMP '1978-07-07 19:38' AT LOCAL, + timezone(TIMESTAMP '1978-07-07 19:38')); +\sv local_time_zone +CREATE OR REPLACE VIEW public.local_time_zone AS + VALUES (('Fri Jul 07 16:38:00 1978 PDT'::timestamp with time zone AT LOCAL),timezone('Fri Jul 07 16:38:00 1978 PDT'::timestamp with time zone),('Fri Jul 07 19:38:00 1978'::timestamp without time zone AT LOCAL),timezone('Fri Jul 07 19:38:00 1978'::timestamp without time zone)) +TABLE local_time_zone; + column1 | column2 | column3 | column4 +--------------------------+--------------------------+------------------------------+------------------------------ + Fri Jul 07 16:38:00 1978 | Fri Jul 07 16:38:00 1978 | Fri Jul 07 19:38:00 1978 PDT | Fri Jul 07 19:38:00 1978 PDT +(1 row) + +DROP VIEW local_time_zone; +COMMIT; -- -- Test that AT TIME ZONE isn't misoptimized when using an index (bug #14504) -- diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql index 69b36d0420..86b83adf68 100644 --- a/src/test/regress/sql/timestamptz.sql +++ b/src/test/regress/sql/timestamptz.sql @@ -611,6 +611,27 @@ SELECT '2014-10-25 22:00:00 UTC'::timestamptz AT TIME ZONE 'MSK'; SELECT '2014-10-25 22:00:01 UTC'::timestamptz AT TIME ZONE 'MSK'; SELECT '2014-10-25 23:00:00 UTC'::timestamptz AT TIME ZONE 'MSK'; +-- +-- Test AT LOCAL +-- +BEGIN; +SET LOCAL TIME ZONE 'Europe/Paris'; +VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL); +VALUES (TIMESTAMP '1978-07-07 19:38' AT LOCAL); +SET LOCAL TIME ZONE 'Australia/Sydney'; +VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL); +VALUES (TIMESTAMP '1978-07-07 19:38' AT LOCAL); +RESET TIME ZONE; +CREATE VIEW local_time_zone AS + VALUES (CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE) AT LOCAL, + timezone(CAST('1978-07-07 19:38 America/New_York' AS TIMESTAMP WITH TIME ZONE)), + TIMESTAMP '1978-07-07 19:38' AT LOCAL, + timezone(TIMESTAMP '1978-07-07 19:38')); +\sv local_time_zone +TABLE local_time_zone; +DROP VIEW local_time_zone; +COMMIT; + -- -- Test that AT TIME ZONE isn't misoptimized when using an index (bug #14504) -- diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index f1ad64c3d6..8047918d0e 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -10611,7 +10611,7 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 - <literal>AT TIME ZONE</literal> + <literal>AT TIME ZONE and AT LOCAL</literal> time zone @@ -10622,6 +10622,10 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 AT TIME ZONE + + AT LOCAL + + The AT TIME ZONE operator converts time stamp without time zone to/from @@ -10632,7 +10636,7 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 - <literal>AT TIME ZONE</literal> Variants + <literal>AT TIME ZONE</literal> and <literal>AT LOCAL</literal> Variants @@ -10665,6 +10669,22 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 + + + timestamp without time zone AT LOCAL + timestamp with time zone + + + Converts given time stamp without time zone to + time stamp with the session's + TimeZone value as time zone. + + + timestamp '2001-02-16 20:38:40' at local + 2001-02-17 03:38:40+00 + + + timestamp with time zone AT TIME ZONE zone @@ -10681,6 +10701,23 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 + + + timestamp with time zone AT LOCAL + timestamp without time zone + + + Converts given time stamp with time zone to + time stamp without time zone, as the time would + appear with the session's TimeZone + value as time zone. + + + timestamp with time zone '2001-02-16 20:38:40-05' at local + 2001-02-16 18:38:40 + + + time with time zone AT TIME ZONE zone @@ -10710,6 +10747,13 @@ SELECT date_bin('15 minutes', TIMESTAMP '2020-02-11 15:44:17', TIMESTAMP '2001-0 UTC, so it is not very common in practice. + + The syntax AT LOCAL may be used as shorthand for + AT TIME ZONE local, where + local is the session's + TimeZone value. + + Examples (assuming the current setting is America/Los_Angeles): @@ -10722,6 +10766,9 @@ SELECT TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-05' AT TIME ZONE 'America/D SELECT TIMESTAMP '2001-02-16 20:38:40' AT TIME ZONE 'Asia/Tokyo' AT TIME ZONE 'America/Chicago'; Result: 2001-02-16 05:38:40 + +SELECT TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-05' AT LOCAL; +Result: 2001-02-16 17:38:40 The first example adds a time zone to a value that lacks it, and displays the value using the current TimeZone @@ -10729,7 +10776,10 @@ SELECT TIMESTAMP '2001-02-16 20:38:40' AT TIME ZONE 'Asia/Tokyo' AT TIME ZONE 'A to the specified time zone, and returns the value without a time zone. This allows storage and display of values different from the current TimeZone setting. The third example converts - Tokyo time to Chicago time. + Tokyo time to Chicago time. The fourth example shifts the time stamp + with time zone value to the time zone currently specified by the + TimeZone setting and returns the value without a + time zone. @@ -10738,6 +10788,12 @@ SELECT TIMESTAMP '2001-02-16 20:38:40' AT TIME ZONE 'Asia/Tokyo' AT TIME ZONE 'A timestamp AT TIME ZONE zone. + + + The function timezone(timestamp) + is equivalent to the SQL-conforming construct timestamp + AT LOCAL. + -- 2.42.0