From a731699566537544652cd09d5ac58ea99bceb2a3 Mon Sep 17 00:00:00 2001 From: damien Date: Thu, 3 Jul 2025 13:13:30 +0000 Subject: [PATCH v2] Generate random dates/times in a specified range This adds 3 new variants of the random() function: random(min date, max date) returns date random(min timestamp, max timestamp) returns timestamp random(min timestamptz, max timestamptz) returns timestamptz Each one returns a random date/timestamp value t in the range min <= t <= max. These functions all rely on the pg_prng_int64_range function developed in PG 17 for the random(bigint,bigint) function. --- doc/src/sgml/func.sgml | 20 ++++ src/backend/utils/adt/pseudorandomfuncs.c | 106 ++++++++++++++++++++-- src/include/catalog/pg_proc.dat | 12 +++ src/test/regress/expected/random.out | 87 ++++++++++++++++++ src/test/regress/sql/random.sql | 26 ++++++ 5 files changed, 243 insertions(+), 8 deletions(-) diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index de5b5929ee0..9677ffa619d 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1926,6 +1926,18 @@ SELECT NOT(ROW(table.*) IS NOT NULL) FROM TABLE; -- detect at least one null in random ( min numeric, max numeric ) numeric + + random ( min date, max date ) + date + + + random ( min timestamp, max timestamp ) + timestamp + + + random ( min timestamptz, max timestamptz ) + timestamptz + Returns a random value in the range min <= x <= max. @@ -1940,6 +1952,14 @@ SELECT NOT(ROW(table.*) IS NOT NULL) FROM TABLE; -- detect at least one null in random(-0.499, 0.499) 0.347 + + + random('1979-02-08'::date,'2025-07-03'::date) + 1983-04-21 + + + random('2000-01-01'::timestamptz, now()) + 2015-09-27 09:11:33.732707+00 diff --git a/src/backend/utils/adt/pseudorandomfuncs.c b/src/backend/utils/adt/pseudorandomfuncs.c index e7b8045f925..c8801d22f8d 100644 --- a/src/backend/utils/adt/pseudorandomfuncs.c +++ b/src/backend/utils/adt/pseudorandomfuncs.c @@ -17,6 +17,9 @@ #include "common/pg_prng.h" #include "miscadmin.h" +#include "utils/builtins.h" +#include "utils/date.h" +#include "utils/datetime.h" #include "utils/fmgrprotos.h" #include "utils/numeric.h" #include "utils/timestamp.h" @@ -25,6 +28,20 @@ static pg_prng_state prng_state; static bool prng_seed_set = false; +/* + * check_range_boundaries() - + * + * throw an error if the range boundaries are inverted + */ +static void +check_range_boundaries(int64 rmin, int64 rmax) +{ + if (rmin > rmax) + ereport(ERROR, + errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("lower bound must be less than or equal to upper bound")); +} + /* * initialize_prng() - * @@ -129,10 +146,7 @@ int4random(PG_FUNCTION_ARGS) int32 rmax = PG_GETARG_INT32(1); int32 result; - if (rmin > rmax) - ereport(ERROR, - errcode(ERRCODE_INVALID_PARAMETER_VALUE), - errmsg("lower bound must be less than or equal to upper bound")); + check_range_boundaries(rmin, rmax); initialize_prng(); @@ -153,10 +167,7 @@ int8random(PG_FUNCTION_ARGS) int64 rmax = PG_GETARG_INT64(1); int64 result; - if (rmin > rmax) - ereport(ERROR, - errcode(ERRCODE_INVALID_PARAMETER_VALUE), - errmsg("lower bound must be less than or equal to upper bound")); + check_range_boundaries(rmin, rmax); initialize_prng(); @@ -183,3 +194,82 @@ numeric_random(PG_FUNCTION_ARGS) PG_RETURN_NUMERIC(result); } + + +/* + * daterandom() - + * + * Returns a random date chosen uniformly in the specified range. + */ +Datum +daterandom(PG_FUNCTION_ARGS) +{ + int32 rmin = (int32) PG_GETARG_DATEADT(0); + int32 rmax = (int32) PG_GETARG_DATEADT(1); + DateADT result; + + check_range_boundaries(rmin, rmax); + + if (rmin == DATEVAL_NOBEGIN || rmax == DATEVAL_NOEND) + ereport(ERROR, + errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("lower and upper bound cannot be infinite")); + + initialize_prng(); + + result = (DateADT) pg_prng_int64_range(&prng_state, rmin, rmax); + + PG_RETURN_DATEADT(result); +} + +/* + * timestamprandom() - + * + * Generate random timestamp chosen uniformly in the specified range. + */ +Datum +timestamprandom(PG_FUNCTION_ARGS) +{ + int64 rmin = (int64) PG_GETARG_TIMESTAMP(0); + int64 rmax = (int64) PG_GETARG_TIMESTAMP(1); + Timestamp result; + + check_range_boundaries(rmin, rmax); + + if (rmin == TIMESTAMP_MINUS_INFINITY || rmax == TIMESTAMP_INFINITY) + ereport(ERROR, + errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("lower and upper bound cannot be infinite")); + + initialize_prng(); + + result = (Timestamp) pg_prng_int64_range(&prng_state, rmin, rmax); + + PG_RETURN_TIMESTAMP(result); +} + +/* + * timestamptzrandom() - + * + * Generate random timestamptz chosen uniformly in the specified range. + */ +Datum +timestamptzrandom(PG_FUNCTION_ARGS) +{ + int64 rmin = (int64) PG_GETARG_TIMESTAMPTZ(0); + int64 rmax = (int64) PG_GETARG_TIMESTAMPTZ(1); + TimestampTz result; + + check_range_boundaries(rmin, rmax); + + if (rmin == TIMESTAMP_MINUS_INFINITY || rmax == TIMESTAMP_INFINITY) + ereport(ERROR, + errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("lower and upper bound cannot be infinite")); + + initialize_prng(); + + result = (TimestampTz) pg_prng_int64_range(&prng_state, rmin, rmax); + + PG_RETURN_TIMESTAMPTZ(result); +} diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 3ee8fed7e53..ce2e1fd6371 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3503,6 +3503,18 @@ proname => 'random', provolatile => 'v', proparallel => 'r', prorettype => 'numeric', proargtypes => 'numeric numeric', proargnames => '{min,max}', prosrc => 'numeric_random' }, +{ oid => '6431', descr => 'random date in range', + proname => 'random', provolatile => 'v', proparallel => 'r', + prorettype => 'date', proargtypes => 'date date', + proargnames => '{min,max}', prosrc => 'daterandom' }, +{ oid => '6432', descr => 'random timestamp in range', + proname => 'random', provolatile => 'v', proparallel => 'r', + prorettype => 'timestamp', proargtypes => 'timestamp timestamp', + proargnames => '{min,max}', prosrc => 'timestamprandom' }, +{ oid => '6433', descr => 'random timestamptz in range', + proname => 'random', provolatile => 'v', proparallel => 'r', + prorettype => 'timestamptz', proargtypes => 'timestamptz timestamptz', + proargnames => '{min,max}', prosrc => 'timestamptzrandom' }, { oid => '1599', descr => 'set random seed', proname => 'setseed', provolatile => 'v', proparallel => 'r', prorettype => 'void', proargtypes => 'float8', prosrc => 'setseed' }, diff --git a/src/test/regress/expected/random.out b/src/test/regress/expected/random.out index 43cf88a3634..fab9e471762 100644 --- a/src/test/regress/expected/random.out +++ b/src/test/regress/expected/random.out @@ -536,3 +536,90 @@ SELECT n, random(0, trim_scale(abs(1 - 10.0^(-n)))) FROM generate_series(-20, 20 20 | 0.60795101234744211935 (41 rows) +-- random dates +SELECT random('1979-02-08'::date,'2025-07-03'::date) AS random_date_multiple_years; + random_date_multiple_years +---------------------------- + 04-09-1986 +(1 row) + +SELECT random('4714-11-24 BC'::date,'5874897-12-31 AD'::date) AS random_date_maximum_range; + random_date_maximum_range +--------------------------- + 10-02-2898131 +(1 row) + +SELECT random('1979-02-08'::date,'1979-02-08'::date) AS random_date_empty_range; + random_date_empty_range +------------------------- + 02-08-1979 +(1 row) + +SELECT random('2024-12-31'::date, '2024-01-01'::date); -- Should error +ERROR: lower bound must be less than or equal to upper bound +SELECT random('-infinity'::date, '2024-01-01'::date); -- Should error +ERROR: lower and upper bound cannot be infinite +SELECT random('2024-12-31'::date, 'infinity'::date); -- Should error +ERROR: lower and upper bound cannot be infinite +-- random timestamps +SELECT random('1979-02-08'::timestamp,'2025-07-03'::timestamp) AS random_timestamp_multiple_years; + random_timestamp_multiple_years +--------------------------------- + Fri Jan 27 18:52:05.366009 2017 +(1 row) + +SELECT random('4714-11-24 BC'::timestamp,'294276-12-31 23:59:59.999999'::timestamp) AS random_timestamp_maximum_range; + random_timestamp_maximum_range +----------------------------------- + Wed Mar 28 00:45:36.180395 226694 +(1 row) + +SELECT random('2024-07-01 12:00:00.000001'::timestamp, '2024-07-01 12:00:00.999999'::timestamp) AS random_narrow_range; + random_narrow_range +--------------------------------- + Mon Jul 01 12:00:00.999286 2024 +(1 row) + +SELECT random('1979-02-08'::timestamp,'1979-02-08'::timestamp) AS random_timestamp_empty_range; + random_timestamp_empty_range +------------------------------ + Thu Feb 08 00:00:00 1979 +(1 row) + +SELECT random('2024-12-31'::timestamp, '2024-01-01'::timestamp); -- Should error +ERROR: lower bound must be less than or equal to upper bound +SELECT random('-infinity'::timestamp, '2024-01-01'::timestamp); -- Should error +ERROR: lower and upper bound cannot be infinite +SELECT random('2024-12-31'::timestamp, 'infinity'::timestamp); -- Should error +ERROR: lower and upper bound cannot be infinite +-- random timestamps with timezone +SELECT random('1979-02-08 +01'::timestamptz,'2025-07-03 +02'::timestamptz) AS random_timestamptz_multiple_years; + random_timestamptz_multiple_years +------------------------------------- + Tue Jun 14 04:41:16.652896 2016 PDT +(1 row) + +SELECT random('4714-11-24 BC +00'::timestamptz,'294276-12-31 23:59:59.999999 +00'::timestamptz) AS random_timestamptz_maximum_range; + random_timestamptz_maximum_range +-------------------------------------- + Wed Mar 26 14:07:16.980265 31603 PDT +(1 row) + +SELECT random('2024-07-01 12:00:00.000001 +04'::timestamptz, '2024-07-01 12:00:00.999999 +04'::timestamptz) AS random_timestamptz_narrow_range; + random_timestamptz_narrow_range +------------------------------------- + Mon Jul 01 01:00:00.835808 2024 PDT +(1 row) + +SELECT random('1979-02-08 +05'::timestamptz,'1979-02-08 +05'::timestamptz) AS random_timestamptz_empty_range; + random_timestamptz_empty_range +-------------------------------- + Wed Feb 07 11:00:00 1979 PST +(1 row) + +SELECT random('2024-01-01 +06'::timestamptz, '2024-01-01 +07'::timestamptz); -- Should error +ERROR: lower bound must be less than or equal to upper bound +SELECT random('-infinity'::timestamptz, '2024-01-01 +07'::timestamptz); -- Should error +ERROR: lower and upper bound cannot be infinite +SELECT random('2024-01-01 +06'::timestamptz, 'infinity'::timestamptz); -- Should error +ERROR: lower and upper bound cannot be infinite diff --git a/src/test/regress/sql/random.sql b/src/test/regress/sql/random.sql index ebfa7539ede..e6edce8159b 100644 --- a/src/test/regress/sql/random.sql +++ b/src/test/regress/sql/random.sql @@ -277,3 +277,29 @@ SELECT random(-1e30, 1e30) FROM generate_series(1, 10); SELECT random(-0.4, 0.4) FROM generate_series(1, 10); SELECT random(0, 1 - 1e-30) FROM generate_series(1, 10); SELECT n, random(0, trim_scale(abs(1 - 10.0^(-n)))) FROM generate_series(-20, 20) n; + +-- random dates +SELECT random('1979-02-08'::date,'2025-07-03'::date) AS random_date_multiple_years; +SELECT random('4714-11-24 BC'::date,'5874897-12-31 AD'::date) AS random_date_maximum_range; +SELECT random('1979-02-08'::date,'1979-02-08'::date) AS random_date_empty_range; +SELECT random('2024-12-31'::date, '2024-01-01'::date); -- Should error +SELECT random('-infinity'::date, '2024-01-01'::date); -- Should error +SELECT random('2024-12-31'::date, 'infinity'::date); -- Should error + +-- random timestamps +SELECT random('1979-02-08'::timestamp,'2025-07-03'::timestamp) AS random_timestamp_multiple_years; +SELECT random('4714-11-24 BC'::timestamp,'294276-12-31 23:59:59.999999'::timestamp) AS random_timestamp_maximum_range; +SELECT random('2024-07-01 12:00:00.000001'::timestamp, '2024-07-01 12:00:00.999999'::timestamp) AS random_narrow_range; +SELECT random('1979-02-08'::timestamp,'1979-02-08'::timestamp) AS random_timestamp_empty_range; +SELECT random('2024-12-31'::timestamp, '2024-01-01'::timestamp); -- Should error +SELECT random('-infinity'::timestamp, '2024-01-01'::timestamp); -- Should error +SELECT random('2024-12-31'::timestamp, 'infinity'::timestamp); -- Should error + +-- random timestamps with timezone +SELECT random('1979-02-08 +01'::timestamptz,'2025-07-03 +02'::timestamptz) AS random_timestamptz_multiple_years; +SELECT random('4714-11-24 BC +00'::timestamptz,'294276-12-31 23:59:59.999999 +00'::timestamptz) AS random_timestamptz_maximum_range; +SELECT random('2024-07-01 12:00:00.000001 +04'::timestamptz, '2024-07-01 12:00:00.999999 +04'::timestamptz) AS random_timestamptz_narrow_range; +SELECT random('1979-02-08 +05'::timestamptz,'1979-02-08 +05'::timestamptz) AS random_timestamptz_empty_range; +SELECT random('2024-01-01 +06'::timestamptz, '2024-01-01 +07'::timestamptz); -- Should error +SELECT random('-infinity'::timestamptz, '2024-01-01 +07'::timestamptz); -- Should error +SELECT random('2024-01-01 +06'::timestamptz, 'infinity'::timestamptz); -- Should error -- 2.39.5