Remove known limitations page

src/current/_data/redirects.yml

@@ -553,6 +553,10 @@
 
 # Removed Pages
 
+- destination: releases/index.md
+  sources: ['known-limitations.md']
+  versions: ['v26.1', 'v25.4']
+
 - destination: licensing-faqs.md
   sources: ['enterprise-licensing.md']
   versions: ['v23.1', 'v23.2', 'v24.1', 'v24.2', 'v24.3']

src/current/_includes/releases/v25.4/v25.4.0.md

@@ -17,7 +17,6 @@ Before [upgrading to CockroachDB v25.4]({% link v25.4/upgrade-cockroach-version.
   - [Features that require upgrade finalization](#v25-4-0-features-that-require-upgrade-finalization)
   - [Key cluster setting changes](#v25-4-0-key-cluster-setting-changes)
   - [Deprecations] (#v25-4-0-deprecations)
-  - [Known limitations](#v25-4-0-known-limitations)
 
 {% include releases/new-release-downloads-docker-image.md release=include.release %}
 
@@ -268,8 +267,4 @@ Before you upgrade, review these changes and other information about the new maj
 
 <h4 id="v25-4-0-deprecations">Deprecations</h4>
 
-{% include releases/v25.4/deprecations.md %}
-
-<h4 id="v25-4-0-known-limitations">Known limitations</h4>
-
-For information about new and unresolved limitations in CockroachDB v25.4, with suggested workarounds where applicable, refer to [Known Limitations]({% link v25.4/known-limitations.md %}).
+{% include releases/v25.4/deprecations.md %}

src/current/_includes/sidebar-all-releases.json

@@ -34,12 +34,6 @@
     "/releases/release-support-policy.html"
   ]
 },
-{
-  "title": "Known Limitations",
-  "urls": [
-    "/${VERSION}/known-limitations.html"
-  ]
-},
 {% assign advisories = site.pages | where_exp: "advisories", "advisories.path contains 'advisories'" | where_exp: "advisories", "advisories.index != 'true'" %}
 {
  "title": "Technical Advisories",

src/current/_includes/sidebar-releases.json

@@ -49,12 +49,6 @@
       "urls": [
         "/releases/release-support-policy.html"
       ]
-    },
-    {
-      "title": "Known Limitations",
-      "urls": [
-        "/${VERSION}/known-limitations.html"
-      ]
     }
   ]
 },

src/current/_includes/v25.4/known-limitations/alter-sequence-limitations.md

@@ -0,0 +1 @@
+- Altering the minimum or maximum value of a series does not check the current value of a series. This means that it is possible to silently set the maximum to a value less than, or a minimum value greater than, the current value. [#23719](https://github.com/cockroachdb/cockroach/issues/23719)

src/current/_includes/v25.4/known-limitations/alter-table-add-column-limitations.md

@@ -0,0 +1,10 @@
+- It is currently not possible to [add a column]({% link {{ page.version.version }}/alter-table.md %}#add-column) to a table when:
+    - The column uses a [sequence]({% link {{ page.version.version }}/create-sequence.md %}) as the [`DEFAULT`]({% link {{ page.version.version }}/default-value.md %}) value, for example using `nextval()`.
+    - The column uses `GENERATED ALWAYS AS IDENTITY` or `GENERATED BY DEFAULT AS IDENTITY`, unless the table being altered is empty.
+
+    This is because CockroachDB does not support back-filling sequential column data. [#42508](https://github.com/cockroachdb/cockroach/issues/42508)
+- When executing an [`ALTER TABLE ADD COLUMN`]({% link {{ page.version.version }}/alter-table.md %}#add-column) statement with a [`DEFAULT`]({% link {{ page.version.version }}/default-value.md %}) expression, new values generated:
+    - Use the default [search path]({% link {{ page.version.version }}/sql-name-resolution.md %}#search-path) regardless of the search path configured in the current session via `SET SEARCH_PATH`.
+    - Use the UTC time zone regardless of the time zone configured in the current session via [`SET TIME ZONE`]({% link {{ page.version.version }}/set-vars.md %}).
+    - Have no default database regardless of the default database configured in the current session via [`SET DATABASE`]({% link {{ page.version.version }}/set-vars.md %}), so you must specify the database of any tables they reference.
+    - Use the transaction timestamp for the `statement_timestamp()` function regardless of the time at which the `ALTER` statement was issued.

src/current/_includes/v25.4/known-limitations/client-connections-limitations.md

@@ -0,0 +1 @@
+- When a node has both a high number of client connections and running queries, the node may crash due to memory exhaustion. This is due to CockroachDB not accurately limiting the number of clients and queries based on the amount of available RAM on the node. To prevent memory exhaustion, monitor each node's memory usage and ensure there is some margin between maximum CockroachDB memory usage and available system RAM. For more details about memory usage in CockroachDB, see [this blog post](https://www.cockroachlabs.com/blog/memory-usage-cockroachdb/).

src/current/_includes/v25.4/known-limitations/collate-limitations.md

@@ -0,0 +1 @@
+- Many string operations are not properly overloaded for [collated strings]({% link {{ page.version.version }}/collate.md %}). For example, the `||` concatenation operator works with regular strings but returns an error with collated strings. [#10679](https://github.com/cockroachdb/cockroach/issues/10679)

src/current/_includes/v25.4/known-limitations/column-family-limitations.md

@@ -0,0 +1 @@
+- When creating or updating a row, if the combined size of all values in a single [column family]({% link {{ page.version.version }}/column-families.md %}) exceeds the [max range size]({% link {{ page.version.version }}/configure-replication-zones.md %}#range-max-bytes) for the table, the operation may fail, or cluster performance may suffer. As a workaround, you can either [manually split a table's columns into multiple column families]({% link {{ page.version.version }}/column-families.md %}#manual-override), or you can [create a table-specific zone configuration]({% link {{ page.version.version }}/configure-replication-zones.md %}#create-a-replication-zone-for-a-table) with an increased max range size.

src/current/_includes/v25.4/known-limitations/comment-on-limitations.md

@@ -0,0 +1 @@
+- The [`COMMENT ON`]({% link {{ page.version.version }}/comment-on.md %}) statement associates comments to databases, tables, or columns. However, the internal table (`system.comments`) in which these comments are stored is not captured by a [`BACKUP`]({% link {{ page.version.version }}/backup.md %}) of an individual table or database. As a workaround, take a cluster backup instead, as the `system.comments` table is included in cluster backups. [#44396](https://github.com/cockroachdb/cockroach/issues/44396)

src/current/_includes/v25.4/known-limitations/composite-type-limitations.md

@@ -0,0 +1,2 @@
+- Updating subfields of composite types using dot syntax results in a syntax error. [#102984](https://github.com/cockroachdb/cockroach/issues/102984)
+- Tuple elements cannot be accessed without enclosing the [composite variable]({% link {{ page.version.version }}/create-type.md %}) name in parentheses. For example, `(OLD).column` and `(NEW).column` when used in [triggers]({% link {{ page.version.version }}/triggers.md %}). [#114687](https://github.com/cockroachdb/cockroach/issues/114687)

src/current/_includes/v25.4/known-limitations/data-domiciling-limitations.md

@@ -1,6 +1,4 @@
-{% if page.name != "known-limitations.md" # New limitations in v25.4 %}
 - When using the `infer_rbr_region_col_using_constraint` option, inserting rows with `DEFAULT` for the region column uses the database's primary region instead of inferring the region from the parent table via foreign-key constraint. [#150783](https://github.com/cockroachdb/cockroach/issues/150783)
-{% endif %}
 - When columns are [indexed]({% link {{ page.version.version }}/indexes.md %}), a subset of data from the indexed columns may appear in [meta ranges]({% link {{ page.version.version }}/architecture/distribution-layer.md %}#meta-ranges) or other system tables. CockroachDB synchronizes these system ranges and system tables across nodes. This synchronization does not respect any multi-region settings applied via either the [multi-region SQL statements]({% link {{ page.version.version }}/multiregion-overview.md %}), or the low-level [zone configs]({% link {{ page.version.version }}/configure-replication-zones.md %}) mechanism.
 - [Zone configs]({% link {{ page.version.version }}/configure-replication-zones.md %}) can be used for data placement but these features were historically built for performance, not for domiciling. The replication system's top priority is to prevent the loss of data and it may override the zone configurations if necessary to ensure data durability. For more information, see [Replication Controls]({% link {{ page.version.version }}/configure-replication-zones.md %}#types-of-constraints).
 - If your [log files]({% link {{ page.version.version }}/logging-overview.md %}) are kept in the region where they were generated, there is some cross-region leakage (like the system tables described previously), but the majority of user data that makes it into the logs is going to be homed in that region. If that's not strong enough, you can use the [log redaction functionality]({% link {{ page.version.version }}/configure-logs.md %}#redact-logs) to strip all raw data from the logs. You can also limit your log retention entirely.

src/current/_includes/v25.4/known-limitations/db-console-limitations.md

@@ -0,0 +1 @@
+- Accessing the DB Console for a secure cluster requires login information (i.e., username and password). This login information is stored in a system table that is replicated like other data in the cluster. If a majority of the nodes with the replicas of the system table data go down, users will be locked out of the DB Console.

src/current/_includes/v25.4/known-limitations/int-limitations.md

@@ -0,0 +1 @@
+- When setting the `default_int_size` [session variable]({% link {{ page.version.version }}/set-vars.md %}) in a batch of statements such as `SET default_int_size='int4'; SELECT 1::INT`, the `default_int_size` variable will not take effect until the next statement. Statement parsing is asynchronous with statement execution. As a workaround, set `default_int_size` via your database driver, or ensure that `SET default_int_size` is in its own statement. [#32846](https://github.com/cockroachdb/cockroach/issues/32846)

src/current/_includes/v25.4/known-limitations/inverted-index-limitations.md

@@ -0,0 +1,3 @@
+- CockroachDB does not allow inverted indexes with a [`STORING` column]({% link {{ page.version.version }}/create-index.md %}#store-columns). [#88278](https://github.com/cockroachdb/cockroach/issues/88278)
+- CockroachDB cannot index-accelerate queries with `@@` predicates when both sides of the operator are variables for `tsvector` and `tsquery` types. [#102731](https://github.com/cockroachdb/cockroach/issues/102731)
+- [Left joins]({% link {{ page.version.version }}/joins.md %}#left-outer-joins) and anti joins involving [`JSONB`]({% link {{ page.version.version }}/jsonb.md %}), [`ARRAY`]({% link {{ page.version.version }}/array.md %}), or [spatial-typed]({% link {{ page.version.version }}/export-spatial-data.md %}) columns with a multi-column or [partitioned]({% link {{ page.version.version }}/alter-index.md %}#partition-by) [GIN index](inverted-indexes.html) will not take advantage of the index if the prefix columns of the index are unconstrained, or if they are constrained to multiple, constant values. To work around this limitation, make sure that the prefix columns of the index are either constrained to single constant values, or are part of an equality condition with an input column. [#59649](https://github.com/cockroachdb/cockroach/issues/59649)

src/current/_includes/v25.4/known-limitations/max-row-size-limitations.md

@@ -0,0 +1 @@
+- The `sql.guardrails.max_row_size_err` [cluster setting]({% link {{ page.version.version }}/cluster-settings.md %}) misses large rows caused by indexed virtual computed columns. This is because the guardrail only checks the size of primary key rows, not secondary index rows. [#69540](https://github.com/cockroachdb/cockroach/issues/69540)

src/current/_includes/v25.4/known-limitations/node-shutdown-limitations.md

@@ -0,0 +1,5 @@
+- There is no guaranteed state switch from `DECOMMISSIONING` to `DECOMMISSIONED` if [`node decommission`]({% link {{ page.version.version }}/cockroach-node.md %}) is interrupted in one of the following ways:
+    - The `cockroach node decommission --wait-all` command was run and then interrupted
+    - The `cockroach node decommission --wait=none` command was run
+
+    This is because the state flip is effected by the CLI program at the end. Only the CLI (or its underlying API call) is able to finalize the "decommissioned" state. If the command is interrupted, or `--wait=none` is used, the state will only flip to "decommissioned" when the CLI program is run again after decommissioning has done all its work. [#94430](https://github.com/cockroachdb/cockroach/issues/94430)

src/current/_includes/v25.4/known-limitations/null-limitations.md

@@ -0,0 +1 @@
+- By default, CockroachDB orders `NULL`s before all other values. For compatibility with PostgreSQL, the `null_ordered_last` [session variable]({% link {{ page.version.version }}/set-vars.md %}) was added, which changes the default to order `NULL` values after all other values. This works in most cases, due to some transformations CockroachDB makes in the optimizer to add extra ordering columns. However, it does not work when the ordering column is a tuple. [#93558](https://github.com/cockroachdb/cockroach/issues/93558)

src/current/_includes/v25.4/known-limitations/online-schema-changes-limitations.md

@@ -22,4 +22,20 @@ You cannot start an online schema change on a table if a [primary key change]({%
 
 ##### No online schema changes between executions of prepared statements
 
-{% include {{ page.version.version }}/known-limitations/schema-changes-between-prepared-statements.md %}
+{% include {{ page.version.version }}/known-limitations/schema-changes-between-prepared-statements.md %}
+
+##### Column-dropping schema changes may not roll back properly
+
+Some [schema changes]({% link {{ page.version.version }}/online-schema-changes.md %}) that [drop columns]({% link {{ page.version.version }}/alter-table.md %}#drop-column) cannot be [rolled back]({% link {{ page.version.version }}/rollback-transaction.md %}) properly.
+
+In some cases, the rollback will succeed, but the column data might be partially or totally missing, or stale due to the asynchronous nature of the schema change. [#46541](https://github.com/cockroachdb/cockroach/issues/46541)
+
+In other cases, the rollback will fail in such a way that will never be cleaned up properly, leaving the table descriptor in a state where no other schema changes can be run successfully. [#47712](https://github.com/cockroachdb/cockroach/issues/47712)
+
+To reduce the chance that a column drop will roll back incorrectly:
+
+- Perform column drops in transactions separate from other schema changes. This ensures that other schema change failures will not cause the column drop to be rolled back.
+- Drop all [constraints]({% link {{ page.version.version }}/constraints.md %}) (including [unique indexes]({% link {{ page.version.version }}/unique.md %})) on the column in a separate transaction, before dropping the column.
+- Drop any [default values]({% link {{ page.version.version }}/default-value.md %}) or [computed expressions]({% link {{ page.version.version }}/computed-columns.md %}) on a column before attempting to drop the column. This prevents conflicts between constraints and default/computed values during a column drop rollback.
+
+If you think a rollback of a column-dropping schema change has occurred, check the [jobs table]({% link {{ page.version.version }}/show-jobs.md %}). Schema changes with an error prefaced by `cannot be reverted, manual cleanup may be required` might require manual intervention.

src/current/_includes/v25.4/known-limitations/partition-limitations.md

@@ -0,0 +1,3 @@
+- When defining a [table partition]({% link {{ page.version.version }}/partitioning.md %}), either during table creation or table alteration, it is not possible to use placeholders in the `PARTITION BY` clause.
+- CockroachDB does not currently support dropping a single partition from a table. In order to remove partitions, you can [repartition]({% unless page.name == "partitioning.md" %}{% link {{ page.version.version }}/partitioning.md %}{% endunless %}#repartition-a-table) the table.
+- In cases where the partition definition includes a comparison with `NULL` and a query constraint, incorrect query plans are returned. However, this case uses non-standard partitioning which defines partitions which could never hold values, so it is not likely to occur in production environments. [#82774](https://github.com/cockroachdb/cockroach/issues/82774)

src/current/_includes/v25.4/known-limitations/plpgsql-limitations.md

@@ -1,5 +1,3 @@
-{% if page.name != "known-limitations.md" # New limitations in v24.2 %}
-{% endif %}
 - It is not possible to use a variable as a target more than once in the same `INTO` clause. For example, `SELECT 1, 2 INTO x, x;`. [#121605](https://github.com/cockroachdb/cockroach/issues/121605)
 - PLpgSQL variable declarations cannot inherit the type of a table row or column using `%TYPE` or `%ROWTYPE` syntax. [#114676](https://github.com/cockroachdb/cockroach/issues/114676)
 - PL/pgSQL arguments cannot be referenced with ordinals (e.g., `$1`, `$2`). [#114701](https://github.com/cockroachdb/cockroach/issues/114701)

src/current/_includes/v25.4/known-limitations/read-committed-limitations.md

@@ -1,6 +1,4 @@
-{% if page.name != "known-limitations.md" # New limitations in v25.4 %}
 - Mixed-isolation-level workloads must enable foreign-key check locking for `SERIALIZABLE` transactions to avoid race conditions. [#151663](https://github.com/cockroachdb/cockroach/issues/151663#issuecomment-3222083180)
-{% endif %}
 - Schema changes (e.g., [`CREATE TABLE`]({% link {{ page.version.version }}/create-table.md %}), [`CREATE SCHEMA`]({% link {{ page.version.version }}/create-schema.md %}), [`CREATE INDEX`]({% link {{ page.version.version }}/create-index.md %})) cannot be performed within explicit `READ COMMITTED` transactions when the [`autocommit_before_ddl` session setting]({% link {{page.version.version}}/set-vars.md %}#autocommit-before-ddl) is set to `off`, and will cause transactions to abort. As a workaround, [set the transaction's isolation level]({% link {{ page.version.version }}/read-committed.md %}#set-the-current-transaction-to-read-committed) to `SERIALIZABLE`. [#114778](https://github.com/cockroachdb/cockroach/issues/114778)
 - Multi-column-family checks during updates are not supported under `READ COMMITTED` isolation. [#112488](https://github.com/cockroachdb/cockroach/issues/112488)
 - Because locks acquired by [foreign key]({% link {{ page.version.version }}/foreign-key.md %}) checks, [`SELECT FOR UPDATE`]({% link {{ page.version.version }}/select-for-update.md %}), and [`SELECT FOR SHARE`]({% link {{ page.version.version }}/select-for-update.md %}) are fully replicated under `READ COMMITTED` isolation, some queries experience a delay for Raft replication.

src/current/_includes/v25.4/known-limitations/routine-limitations.md

@@ -1,5 +1,3 @@
-{% if page.name != "known-limitations.md" # New limitations in v24.2 %}
-{% endif %}
 - Routines cannot be invoked with named arguments, e.g., `SELECT foo(a => 1, b => 2);` or `SELECT foo(b := 1, a := 2);`. [#122264](https://github.com/cockroachdb/cockroach/issues/122264)
 - Routines cannot be created if they reference temporary tables. [#121375](https://github.com/cockroachdb/cockroach/issues/121375)
 - Routines cannot be created with unnamed `INOUT` parameters. For example, `CREATE PROCEDURE p(INOUT INT) AS $$ BEGIN NULL; END; $$ LANGUAGE PLpgSQL;`. [#121251](https://github.com/cockroachdb/cockroach/issues/121251)

src/current/_includes/v25.4/known-limitations/savepoint-limitations.md

@@ -0,0 +1 @@
+- Transactions with [priority `HIGH`]({% link {{ page.version.version }}/transactions.md %}#transaction-priorities) that contain DDL and `ROLLBACK TO SAVEPOINT` are not supported, as they could result in a deadlock. [#46414](https://github.com/cockroachdb/cockroach/issues/46414)