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Fix timestamp overflow in UUIDv7 implementation.

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The uuidv7_interval() function previously converted a shifted
microsecond-precision timestamp (64-bit integer) to another 64-bit
integer representing a timestamp with nanosecond precision. This
conversion caused overflow for dates beyond the year 2262. The
millisecond and sub-millisecond parts were then extracted from this
nanosecond-precision timestamp and stored in UUIDv7 values.

With this commit, the millisecond and sub-millisecond parts are stored
directly into the UUIDv7 value without being converted back to a
nanosecond precision timestamp. Following RFC 9562, the timestamp is
stored as an unsigned integer, enabling support for dates up to the
year 10889.

Reported and fixed by Andrey Borodin, with cosmetic changes and
regression tests by me.

Reported-by: Andrey Borodin <x4mmm@yandex-team.ru>
Author: Andrey Borodin <x4mmm@yandex-team.ru>
Discussion: https://postgr.es/m/96DEC2D9-659A-40E8-B7BA-AF5D162A9E21@yandex-team.ru
This commit is contained in:
Masahiko Sawada
2025-03-28 09:39:11 -07:00
parent 8e993bff53
commit a5419bc72e
3 changed files with 44 additions and 17 deletions
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15
src/test/regress/expected/uuid.out
View File

@@ -233,6 +233,21 @@ SELECT array_agg(id ORDER BY guid_field) FROM guid3;
{1,2,3,4,5,6,7,8,9,10}
(1 row)
-- Check the timestamp offsets for v7.
--
-- generate UUIDv7 values with timestamps ranging from 1970 (the Unix epoch year)
-- to 10888 (one year before the maximum possible year), and then verify that
-- the extracted timestamps from these UUIDv7 values have not overflowed.
WITH uuidts AS (
SELECT y, ts as ts, lag(ts) OVER (ORDER BY y) AS prev_ts
FROM (SELECT y, uuid_extract_timestamp(uuidv7((y || ' years')::interval)) AS ts
FROM generate_series(1970 - extract(year from now())::int, 10888 - extract(year from now())::int) y)
)
SELECT y, ts, prev_ts FROM uuidts WHERE ts < prev_ts;
y | ts | prev_ts
---+----+---------
(0 rows)
-- extract functions
-- version
SELECT uuid_extract_version('11111111-1111-5111-8111-111111111111'); -- 5

12
src/test/regress/sql/uuid.sql
View File

@@ -119,6 +119,18 @@ SELECT count(DISTINCT guid_field) FROM guid1;
INSERT INTO guid3 (guid_field) SELECT uuidv7() FROM generate_series(1, 10);
SELECT array_agg(id ORDER BY guid_field) FROM guid3;
-- Check the timestamp offsets for v7.
--
-- generate UUIDv7 values with timestamps ranging from 1970 (the Unix epoch year)
-- to 10888 (one year before the maximum possible year), and then verify that
-- the extracted timestamps from these UUIDv7 values have not overflowed.
WITH uuidts AS (
SELECT y, ts as ts, lag(ts) OVER (ORDER BY y) AS prev_ts
FROM (SELECT y, uuid_extract_timestamp(uuidv7((y || ' years')::interval)) AS ts
FROM generate_series(1970 - extract(year from now())::int, 10888 - extract(year from now())::int) y)
)
SELECT y, ts, prev_ts FROM uuidts WHERE ts < prev_ts;
-- extract functions
-- version