Release Notes for v26.2-v26.2.1

src/current/_data/releases.yml

@@ -11537,3 +11537,38 @@
     docker_arm_limited_access: false
   source: true
   previous_release: v24.1.28
+
+
+- release_name: v26.2.1
+  major_version: v26.2
+  release_date: '2026-05-22'
+  release_type: Production
+  go_version: go1.26.2
+  sha: 218386f198731b3a7d73a81ce8fdc6c70956b5df
+  has_sql_only: true
+  has_sha256sum: true
+  mac:
+    mac_arm: true
+    mac_arm_experimental: true
+    mac_arm_limited_access: false
+  windows: true
+  linux:
+    linux_arm: true
+    linux_arm_experimental: false
+    linux_arm_limited_access: false
+    linux_intel_fips: true
+    linux_arm_fips: false
+  docker:
+    docker_image: cockroachdb/cockroach
+    docker_arm: true
+    docker_arm_experimental: false
+    docker_arm_limited_access: false
+  source: true
+  previous_release: v26.2.0
+  cloud_only: true
+  cloud_only_message_short: 'Available only for select CockroachDB Cloud clusters'
+  cloud_only_message: >
+      This version is currently available only for select
+      CockroachDB Cloud clusters. To request to upgrade
+      a CockroachDB self-hosted cluster to this version,
+      [contact support](https://support.cockroachlabs.com/hc/requests/new).

src/current/_includes/releases/v26.2/v26.2.1.md

@@ -0,0 +1,132 @@
+## v26.2.1
+
+Release Date: May 22, 2026
+
+{% include releases/new-release-downloads-docker-image.md release=include.release %}
+
+<h3 id="v26-2-1-sql-language-changes">SQL language changes</h3>
+
+- The canary_stats_mode session variable values
+  are renamed from "off"/"on" to "force_stable"/"force_canary". These modes
+  now work independently of the sql.stats.canary_fraction cluster setting,
+  allowing per-session opt-in without cluster-wide enrollment.
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#168295][#168295]
+- Add a new session variable
+  `optimizer_span_limit` which bounds the number of spans the optimizer
+  will allow in a single constrained index scan. If a single IN set has
+  more items than this limit, that IN set will not be used to build a
+  constrained index scan. If the cross product of two or more IN sets
+  would produce more spans than this limit for a composite index, then
+  only a prefix of the IN sets will be used to produce spans.
+
+  For example, for the following table and query, only the predicates on
+  columns `a` and `b` will be used to construct the constrained scan of
+  `abc_idx`, because including the predicate on column `c` would produce
+  more spans than `optimizer_span_limit`:
+
+  ```sql
+  CREATE TABLE abc (a INT, b INT, c INT, INDEX abc_idx (a, b, c));
+  SET optimizer_span_limit = 10;
+  SELECT * FROM abc WHERE a IN (1, 3, 5) AND b IN (2, 4, 6) AND c IN (7, 9, 11);
+  ```
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#168617][#168617]
+- The new cluster setting
+  `sql.stats.table_statistics_cache.capacity` controls the maximum number
+  of tables whose statistics are retained in the in-memory LRU cache
+  (default: 256).
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169247][#169247]
+
+<h3 id="v26-2-1-operational-changes">Operational changes</h3>
+
+- The following cluster settings are now
+  documented and publicly visible: obs.ash.enabled,
+  obs.ash.sample_interval, obs.ash.buffer_size, obs.ash.log_interval,
+  obs.ash.log_top_n, and obs.ash.response_limit.
+
+  Epic: none
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#168799][#168799]
+- Three new admission control metrics are now
+  available for monitoring disk bandwidth token usage:
+  admission.granter.disk_write_byte_tokens_used.regular.kv,
+  admission.granter.disk_write_byte_tokens_used.elastic.kv, and
+  admission.granter.disk_write_byte_tokens_used.snapshot.kv. The existing
+  admission.granter.disk_write_byte_tokens_exhausted_duration.kv metric
+  is now marked as essential and will appear on the Overload dashboard.
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169713][#169713]
+- Four new gauges `mma.overloaded_store.{lease_grace,short_dur,medium_dur,long_dur}.blocked` report overloaded stores that the multi-metric allocator (MMA) deferred because they already had too much pending work. Per duration bucket, success + failure + blocked equals the count of overloaded stores observed. A persistently non-zero value on the `long_dur.blocked` gauge indicates an overloaded store that is repeatedly being deferred and may not be receiving relief. [#169742][#169742]
+
+<h3 id="v26-2-1-bug-fixes">Bug fixes</h3>
+
+- Fixed a bug where transient I/O errors reading from the `AbortSpan` were misidentified as replica corruption, causing the node to crash. These errors are now returned to the caller as regular errors. [#168014][#168014]
+- Fixed a bug where DB Console Databases page
+  privilege checks did not resolve role membership chains for CONNECT
+  grants. Users who inherited CONNECT through role hierarchies now
+  correctly see their authorized databases and tables.
+
+  Epic: none
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#168496][#168496]
+- Fixed a bug under the declarative schema
+  changer where `ALTER TABLE ... DROP CONSTRAINT <pk>, ADD PRIMARY KEY
+  (...)` would leave behind an unwanted unique secondary index on the
+  old primary key columns. [#168967][#168967]
+- Stopped logging a spurious "declarative schema changer does not support DISCARD" message every time a `DISCARD` statement was executed. The message had no functional impact but could produce very high log volume on busy clusters that issue `DISCARD` on every connection checkout. [#169077][#169077]
+- A physical cluster replication reader tenant no longer fails authentication and other queries with errors of the form "resolved <name> to <id> but found no descriptor with id <id>" after the reader tenant ingests a system table at an ID different from the one it was bootstrapped with. Previously, a per-node namespace cache could pin the bootstrap-time ID and require a tenant restart to recover. [#169139][#169139]
+- Fixed a panic during CREATE VECTOR INDEX
+  backfill when the table contained a public column ordered before the
+  vector column that was not stored in the source primary index and was
+  not referenced by the new index. In practice this was triggered by
+  virtual computed columns. The schema change crashed the SQL node
+  processing the backfill instead of completing.
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169250][#169250]
+- Fixed a bug where unqualified function calls
+  could fail with incorrect privilege errors when two databases on the
+  same cluster had identically-named functions in custom schemas. The
+  query cache could serve a memo from one database context to another,
+  causing USAGE privilege errors referencing schemas from the wrong
+  database.
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169291][#169291]
+- Fixed a bug where PCR reader tenants could
+  permanently fail authentication after SetupOrAdvanceStandbyReaderCatalog
+  rewrote the system.privileges namespace entry. A stale cached name→ID
+  mapping was never refreshed, causing every SQL connection to fail with
+  "descriptor not found".
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169389][#169389]
+- Fixed a bug where RESTORE TABLE of a
+  multi-region table backed up mid-ALTER TABLE ... SET LOCALITY would
+  fail with a descriptor rewrite error.
+
+  Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> [#169425][#169425]
+- Fixed a data race in the multi-metric allocator
+  between gossip-driven store load updates and concurrent lease/replica
+  rebalancing decisions.
+
+  Epic: CRDB-56265
+
+  Co-Authored-By: roachdev-claude <roachdev-claude-bot@cockroachlabs.com> [#169590][#169590]
+
+
+[#169291]: https://github.com/cockroachdb/cockroach/pull/169291
+[#169425]: https://github.com/cockroachdb/cockroach/pull/169425
+[#169077]: https://github.com/cockroachdb/cockroach/pull/169077
+[#168014]: https://github.com/cockroachdb/cockroach/pull/168014
+[#168967]: https://github.com/cockroachdb/cockroach/pull/168967
+[#168496]: https://github.com/cockroachdb/cockroach/pull/168496
+[#169139]: https://github.com/cockroachdb/cockroach/pull/169139
+[#169389]: https://github.com/cockroachdb/cockroach/pull/169389
+[#169590]: https://github.com/cockroachdb/cockroach/pull/169590
+[#168617]: https://github.com/cockroachdb/cockroach/pull/168617
+[#169247]: https://github.com/cockroachdb/cockroach/pull/169247
+[#169713]: https://github.com/cockroachdb/cockroach/pull/169713
+[#169742]: https://github.com/cockroachdb/cockroach/pull/169742
+[#169250]: https://github.com/cockroachdb/cockroach/pull/169250
+[#168295]: https://github.com/cockroachdb/cockroach/pull/168295
+[#168799]: https://github.com/cockroachdb/cockroach/pull/168799