Release Notes for v25.4-v25.4.0-rc.1 (#20655)

* Update release notes for v25.4-v25.4.0-rc.1

* Update release notes for v25.4-v25.4.0-rc.1

* Update release notes for v25.4-v25.4.0-rc.1

* Update release notes for v25.4-v25.4.0-rc.1

* Update release notes for v25.4-v25.4.0-rc.1

* Update release notes for v25.4-v25.4.0-rc.1

* Added missing version

Added missing version 25.3.3 to resolve merge conflict

* Update v25.4.0-rc.1.md

Small format/grammar changes

---------

Co-authored-by: Automated Release Bot <releasebot@cockroachlabs.com>
Co-authored-by: Peach Leach <peach.leach@cockroachlabs.com>
Co-authored-by: Peach Leach <87079419+peachdawnleach@users.noreply.github.com>

Author: 3 people

src/current/_data/releases.yml

@@ -9723,7 +9723,7 @@
       a CockroachDB self-hosted cluster to this version,
       [contact support](https://support.cockroachlabs.com/hc/requests/new).
 
-      
+
 - release_name: v25.3.3
   major_version: v25.3
   release_date: '2025-10-17'
@@ -9756,4 +9756,32 @@
       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).
+      [contact support](https://support.cockroachlabs.com/hc/requests/new).
+
+
+- release_name: v25.4.0-rc.1
+  major_version: v25.4
+  release_date: '2025-10-22'
+  release_type: Testing
+  go_version: go1.23.12
+  sha: 1de9c4bc217dca385a4f912dbdf828bc5629711a
+  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-unstable
+    docker_arm: true
+    docker_arm_experimental: false
+    docker_arm_limited_access: false
+  source: true
+  previous_release: v25.4.0-beta.3

src/current/_includes/releases/v25.4/v25.4.0-rc.1.md

@@ -0,0 +1,49 @@
+## v25.4.0-rc.1
+
+Release Date: October 22, 2025
+
+{% include releases/new-release-downloads-docker-image.md release=include.release %}
+
+<h3 id="v25-4-0-rc-1-sql-language-changes">SQL language changes</h3>
+
+- Changed scan misestimate logging gated behind
+  `sql.log.scan_row_count_misestimate.enabled` to use structured logging
+  including the table and index being scanned, the estimated and actual
+  row counts, the time since the last table stats collection, and the
+  table's estimated staleness. [#155123][#155123]
+- Added a default-off cluster setting
+  (`sql.log.scan_row_count_misestimate.enabled`) that enables logging a
+  warning on the gateway node when optimizer estimates for scans are
+  inaccurate. The log message includes the table and index being scanned,
+  the estimated and actual row counts, the time since the last table stats
+  collection, and the table's estimated staleness. [#155123][#155123]
+- Added the `INSPECT` command, which runs consistency validation check jobs against tables or databases and specified indexes. [#155441][#155441]
+- Added the
+  `bulkio.index_backfill.vector_merge_batch_size cluster` setting to control
+  how many vectors to merge into a vector index per transaction during
+  create operations. By default, this defaults to 3. [#155509][#155509]
+- Vector indexing is now enabled by default. [#155561][#155561]
+
+<h3 id="v25-4-0-rc-1-bug-fixes">Bug fixes</h3>
+
+- Fixed a bug that caused internal errors for `INSERT .. ON CONFLICT .. DO UPDATE` statements when the target table had both a computed column and a `BEFORE` trigger. This bug was present since triggers were introduced in v24.3.0. [#155077][#155077]
+- Disable a feature
+  (`kv.lock_table.unreplicated_lock_reliability.split.enabled`) that could
+  lead to a node crash. [#155366][#155366]
+- Previously, we could corrupt the first bucket of
+  table statistic histograms in certain cases, causing underestimates for
+  range counts near the lower end of the domain, which is now fixed. [#155415][#155415]
+- A potential deadlock during vector index
+  creation has been corrected. [#155508][#155508]
+- Added proper dependency handling when adding a constraint with `NOT VALID` that references a user-defined function (UDF). [#155528][#155528]
+
+
+[#155123]: https://github.com/cockroachdb/cockroach/pull/155123
+[#155441]: https://github.com/cockroachdb/cockroach/pull/155441
+[#155508]: https://github.com/cockroachdb/cockroach/pull/155508
+[#155509]: https://github.com/cockroachdb/cockroach/pull/155509
+[#155561]: https://github.com/cockroachdb/cockroach/pull/155561
+[#155077]: https://github.com/cockroachdb/cockroach/pull/155077
+[#155366]: https://github.com/cockroachdb/cockroach/pull/155366
+[#155415]: https://github.com/cockroachdb/cockroach/pull/155415
+[#155528]: https://github.com/cockroachdb/cockroach/pull/155528