fix(partitioning): render chunk names from the UTC instant

CHANGELOG.md

@@ -8,6 +8,14 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), version
 
 ## [Unreleased]
 
+## [0.1.3] - 2026-06-09
+
+### Fixed
+
+- **Timezone-stable chunk names.** `_ensure_partitions` rendered `chunk_name` with `to_char(range_start, …)` in the **session timezone**, while `range_start` is an absolute `timestamptz`. Running the partition manager under different session timezones (e.g. a job in UTC vs a client in UTC+2) produced names that no longer matched `range_start`, so the partition manager hit `duplicate key value violates unique constraint "idx_chunk_metadata_chunk_name"` (the `ON CONFLICT (chronotable_id, range_start)` couldn't absorb a `chunk_name` collision). Names are now rendered from the instant in UTC (`v_start AT TIME ZONE 'UTC'`), keeping `chunk_name` 1:1 with `range_start` regardless of session timezone.
+
+Upgrade by reinstalling `dist/lakets.sql`. Any chunk rows created before this fix under a non-UTC session keep their old names; if the partition manager still collides, drop the stale rows for already-dropped chunks (their partitions are gone) and let it recreate them.
+
 ## [0.1.2] - 2026-06-08
 
 ### Fixed

VERSION

@@ -1 +1 @@
-0.1.2
+0.1.3

sql/00_version.sql

@@ -22,7 +22,7 @@ SET client_min_messages TO NOTICE;
 DO $$
 DECLARE
     v_installed       TEXT;
-    v_incoming        TEXT := coalesce(nullif('__LAKETS_VERSION__', '__LAKE' || 'TS_VERSION__'), '0.1.2');
+    v_incoming        TEXT := coalesce(nullif('__LAKETS_VERSION__', '__LAKE' || 'TS_VERSION__'), '0.1.3');
     v_installed_parts INT[];
     v_incoming_parts  INT[];
 BEGIN

sql/02_chronotable.sql

@@ -64,16 +64,21 @@ BEGIN
               AND status != 'dropped'
         ) THEN
             BEGIN
+                -- Render the chunk name from the absolute instant in UTC. range_start
+                -- is a timestamptz, so to_char in the session timezone would name the
+                -- same chunk differently across sessions (e.g. a job in UTC vs a client
+                -- in UTC+2), desyncing chunk_name from range_start and colliding on the
+                -- chunk_name unique index. UTC keeps the name 1:1 with range_start.
                 EXECUTE format(
                     'CREATE TABLE IF NOT EXISTS %I.%I PARTITION OF %I.%I FOR VALUES FROM (%L) TO (%L)',
                     v_schema,
-                    v_table || '_' || to_char(v_start, 'YYYYMMDD_HH24MISS'),
+                    v_table || '_' || to_char(v_start AT TIME ZONE 'UTC', 'YYYYMMDD_HH24MISS'),
                     v_schema, v_table, v_start, v_end
                 );
                 INSERT INTO lakets._chunk_metadata
                     (chronotable_id, chunk_name, range_start, range_end, status)
                 VALUES (p_chronotable_id,
-                        v_schema || '.' || v_table || '_' || to_char(v_start, 'YYYYMMDD_HH24MISS'),
+                        v_schema || '.' || v_table || '_' || to_char(v_start AT TIME ZONE 'UTC', 'YYYYMMDD_HH24MISS'),
                         v_start, v_end, 'active')
                 ON CONFLICT (chronotable_id, range_start) DO NOTHING;
                 v_partitions_created := v_partitions_created + 1;