Remove mention of 'declarative' schema changer' (#19443)

* Remove mention of 'declarative' schema changer'

Fixes DOC-8693

Summary:

- Remove mentions of "declarative schema changer" (DSC) for the
  following reasons:

  - 1. It is enabled by default, and 99% of users will never change the
    relevant setting or even need to know what that is.

  - 2. Its existence is an internal implementation detail that is fine
    for internal TSE runbooks to refer to, but should not really be in
    customer-facing docs since "it uses two different implementations on
    the inside, one of which we're migrating away from" should not be a
    thing that matters to 99% of users unless there is a specific
    problem they are working with TSE to solve.

* NB. Ported these changes from v23.1 up to v25.2

Author: rmloveland

src/current/_includes/releases/v23.1/v23.1.0-alpha.1.md

@@ -47,7 +47,7 @@ Release Date: December 19, 2022
 - A new column `plan_gist` was added to `crdb_internal.{node,cluster}_queries` representing the compressed logical plan. [#88770][#88770]
 - You can generate easy-to-read [`CREATE INDEX`]({% link v23.1/create-index.md %}) statements for a table's (secondary) indexes using the `SHOW CREATE INDEXES FROM <table_name>` and `SHOW CREATE SECONDARY INDEXES FROM <table_name>` statements. [#88861][#88861]
 - `enum_first`, `enum_last`, and `enum_range` may now take `NULL` arguments as long as their type can be inferred from the expression. [#89124][#89124]
-- [Declarative schema changer]({% link v23.1/online-schema-changes.md %}#declarative-schema-changer) support for `ALTER PRIMARY KEY` statements now extends to tables which have secondary indexes. [#86176][#86176]
+- [Declarative schema changer]({% link v23.1/online-schema-changes.md %}) support for `ALTER PRIMARY KEY` statements now extends to tables which have secondary indexes. [#86176][#86176]
 - The `backup.restore_span.target_size` cluster setting now defaults to `384 MiB `. This should reduce the number of ranges created during [restore]({% link v23.1/restore.md %}) and thereby reduce the merging of ranges that needs to occur after the restore. [#89333][#89333]
 - The `transaction_timeout` [session variable]({% link v23.1/set-vars.md %}) was added. `transaction_timeout` aborts an explicit transaction when it runs longer than the configured duration. When the timer times out, the current statement is cancelled and the transaction enters an aborted state. This timeout does not have any effect when no statement is being executed, so it should be used with `idle_in_transaction_timeout` for the best results. [#89033][#89033]
 - The `crdb_internal.check_consistency` [function]({% link v23.1/functions-and-operators.md %}) now does not include the diff between inconsistent replicas, should they occur. If an inconsistency occurs, the storage engine checkpoints should be inspected. This change is made because the maximum range size limit has been increased from 64 MiB to 512 MiB, so inlining diffs in consistency checks does not scale. [#89502][#89502]
@@ -83,7 +83,7 @@ Release Date: December 19, 2022
 - Added a list of used indexes (with the format `tableID@indexID`) to the sampled query telemetry log. [#92464][#92464]
 - A new `NumericStat`, `idleLat`, was introduced to the statistics column of `crdb_internal.transaction_statistics`. It reports the time spent waiting for the client to send statements while holding a transaction open. [#92695][#92695]
 - Added an in-memory-only evaluation of `tsvector` and `tsquery` datatypes and the `@@` matches operator. [#90842][#90842]
-- Implemented the [`ALTER TABLE ... ADD CHECK`]({% link v23.1/alter-table.md %}) statement in the [declarative schema changer]({% link v23.1/online-schema-changes.md %}#declarative-schema-changer). [#91153][#91153]
+- Implemented the [`ALTER TABLE ... ADD CHECK`]({% link v23.1/alter-table.md %}) statement in the [declarative schema changer]({% link v23.1/online-schema-changes.md %}). [#91153][#91153]
 - `to_char` now has caching for parse formats, marking a speedup when running `to_char` with the same format between sessions. [#91564][#91564]
 - Casts from index name to `REGCLASS` are now supported. Previously, only table names could be cast to `REGCLASS`. [#90649][#90649]
 - Added user-defined composite column types. [#90491][#90491]

src/current/_includes/releases/v23.1/v23.1.0.md

@@ -113,13 +113,13 @@ SELECT (a).b FROM a</pre>
   <tr>
    <td><p>Declarative schema changer supports user-defined functions UDFs</p>
    </td>
-   <td><p>The statements <code>CREATE FUNCTION</code> and <code>DROP FUNCTION</code> are now supported by the <a href="https://www.cockroachlabs.com/docs/v23.1/online-schema-changes#declarative-schema-changer">declarative schema changer</a>.
+   <td><p>The statements <code>CREATE FUNCTION</code> and <code>DROP FUNCTION</code> are now supported by the <a href="https://www.cockroachlabs.com/docs/v23.1/online-schema-changes">declarative schema changer</a>.
    </td>
   </tr>
   <tr>
    <td><p>Declarative schema changer fully supports constraints </p>
    </td>
-   <td><p> The statements <code>ALTER TABLE...ADD CONSTRAINT</code> and <code>ALTER TABLE...DROP CONSTRAINT</code> are now supported by the <a href="https://www.cockroachlabs.com/docs/v23.1/online-schema-changes#declarative-schema-changer">declarative schema changer</a>.</td>
+   <td><p> The statements <code>ALTER TABLE...ADD CONSTRAINT</code> and <code>ALTER TABLE...DROP CONSTRAINT</code> are now supported by the <a href="https://www.cockroachlabs.com/docs/v23.1/online-schema-changes">declarative schema changer</a>.</td>
   </tr>
   <tr>
    <td><p>Add configurable setting to adjust grant lease options </p>

src/current/_includes/releases/v23.1/v23.1.13.md

@@ -37,15 +37,15 @@ Release Date: December 11, 2023
 - Fixed a bug introduced in v22.2 where CockroachDB could incorrectly evaluate [lookup and index joins](https://www.cockroachlabs.com/docs/v23.1/joins.html) into tables with at least 3 [column families](https://www.cockroachlabs.com/docs/v23.1/column-families.html) in some cases (either a `non-nullable column with no value` internal error would occur, or the query would return incorrect results). [#113108][#113108]
 - Fixed a bug that could occasionally cause [schema change jobs](https://www.cockroachlabs.com/docs/v23.1/online-schema-changes.html) (e.g., table/index drops) to appear stuck in state "waiting for MVCC GC" for much longer than expected. This fix only applies to future schema changes. Existing stuck jobs can be processed by manually force-enqueueing the relevant [ranges](https://www.cockroachlabs.com/docs/v23.1/architecture/overview.html#architecture-range) in the MVCC GC queue under the [DB Console's **Advanced Debug** page](https://www.cockroachlabs.com/docs/v23.1/ui-debug-pages.html). [#110643][#110643]
 - Fixed a bug that could cause internal errors or panics while attempting to forecast [statistics](https://www.cockroachlabs.com/docs/v23.1/cost-based-optimizer.html#table-statistics) on a numeric column. [#113798][#113798]
-- Fixed a bug where [`ALTER PRIMARY KEY`](https://www.cockroachlabs.com/docs/v23.1/alter-table.html#alter-primary-key) would incorrectly disable [secondary indexes](https://www.cockroachlabs.com/docs/v23.1/indexes.html) while new secondary indexes were being backfilled when using the [declarative schema changer](https://www.cockroachlabs.com/docs/v23.1/online-schema-changes.html#declarative-schema-changer). [#113183][#113183]
+- Fixed a bug where [`ALTER PRIMARY KEY`](https://www.cockroachlabs.com/docs/v23.1/alter-table.html#alter-primary-key) would incorrectly disable [secondary indexes](https://www.cockroachlabs.com/docs/v23.1/indexes.html) while new secondary indexes were being backfilled when using the [declarative schema changer](https://www.cockroachlabs.com/docs/v23.1/online-schema-changes.html). [#113183][#113183]
 - Previously, when executing queries with [index / lookup joins](https://www.cockroachlabs.com/docs/v23.1/joins.html) when the ordering needs to be maintained, CockroachDB could in some cases inadvertently increase query latency, possibly by 1 or 2 orders of magnitude. This bug was introduced in v22.2 and is now fixed. [#114143][#114143]
 - Fixed a bug where the [`SHOW STATISTICS`](https://www.cockroachlabs.com/docs/v23.1/show-statistics.html) command would incorrectly require the user to have the [admin role](https://www.cockroachlabs.com/docs/v23.1/security-reference/authorization.html#admin-role). It was intended to only require the user to have any privilege on the table being inspected. [#114479][#114479]
 - Fixed a bug that could cause a query plan to skip scanning rows from the local region when performing a [lookup join](https://www.cockroachlabs.com/docs/v23.1/joins.html) with a [`REGIONAL BY ROW`](https://www.cockroachlabs.com/docs/v23.1/table-localities.html#regional-by-row-tables) table as the input. [#114456][#114456]
 - Fixed a bug that could cause [`ALTER DATABASE ... ADD/DROP REGION`](https://www.cockroachlabs.com/docs/v23.1/alter-database.html#add-region) to hang if node localities were changed after regions were added. [#114197][#114197]
 
 <h3 id="v23-1-13-performance-improvements">Performance improvements</h3>
 
-- Addressed a performance regression that could happen when the [declarative schema changer](https://www.cockroachlabs.com/docs/v23.1/online-schema-changes.html#declarative-schema-changer) is being used to [create an index](https://www.cockroachlabs.com/docs/v23.1/create-index.html) with a concurrent workload. [#113724][#113724]
+- Addressed a performance regression that could happen when the [declarative schema changer](https://www.cockroachlabs.com/docs/v23.1/online-schema-changes.html) is being used to [create an index](https://www.cockroachlabs.com/docs/v23.1/create-index.html) with a concurrent workload. [#113724][#113724]
 - Added an off-by-default [cluster setting](https://www.cockroachlabs.com/docs/v23.1/cluster-settings.html), `kv.dist_sender.follower_reads_unhealthy.enabled`, which when enabled will prevent failed requests from being issued on followers that are [draining](https://www.cockroachlabs.com/docs/v23.1/node-shutdown.html#draining), [decommissioning](https://www.cockroachlabs.com/docs/v23.1/node-shutdown?filters=decommission), or otherwise unhealthy. This will prevent [follower reads](https://www.cockroachlabs.com/docs/v23.1/follower-reads.html) against nodes in such states. This prevents latency spikes if those nodes later go offline. [#114367][#114367]
 - [Query planning](https://www.cockroachlabs.com/docs/v23.1/cost-based-optimizer.html) time has been reduced significantly for some queries in which many tables are [joined](https://www.cockroachlabs.com/docs/v23.1/joins.html). [#114835][#114835]
 

src/current/_includes/releases/v23.1/v23.1.24.md

@@ -16,7 +16,7 @@ Release Date: July 18, 2024
 
 <h3 id="v23-1-24-bug-fixes">Bug fixes</h3>
 
-- Fixed handling in the [declarative schema changer]({% link v23.1/online-schema-changes.md %}#declarative-schema-changer) when columns are included in the `STORING()` clause of [`CREATE INDEX`]({% link v23.1/create-index.md %}). CockroachDB now checks if the column is virtual up-front, and properly detects when a column is already handled by an existing index when the column name has `UTF-8` characters. [#125208][#125208]
+- Fixed handling in the [declarative schema changer]({% link v23.1/online-schema-changes.md %}) when columns are included in the `STORING()` clause of [`CREATE INDEX`]({% link v23.1/create-index.md %}). CockroachDB now checks if the column is virtual up-front, and properly detects when a column is already handled by an existing index when the column name has `UTF-8` characters. [#125208][#125208]
 - Fixed a bug where a change to a [user-defined type (UDT)]({% link v23.1/create-type.md %}) could cause queries against tables using that type to fail with an error message like: `histogram.go:694: span must be fully contained in the bucket`. The change to the user-defined type could occur either directly from an [`ALTER TYPE`]({% link v23.1/alter-type.md %} statement or indirectly from an [`ALTER DATABASE ... ADD REGION`]({% link v23.1/alter-database.md %}#add-region) or [`ALTER DATABASE ... DROP REGION`]({% link v23.1/alter-database.md %}#drop-region) statement, which implicitly modifies the `crdb_internal_region` UDT. This bug had existed since UDTs were introduced in v20.2. [#124855][#124855]
 - Fixed an issue where [adding a column]({% link v23.1/alter-table.md %}#add-column) with a default value of an empty array would not succeed. [#125328][#125328]
 - [`ALTER TABLE ... ADD CONSTRAINT UNIQUE`]({% link v23.1/alter-table.md %}#add-constraint) will now fail with a well-formed error message and code `42601` if a statement tries to add a unique constraint on an expression. [#125420][#125420]

src/current/_includes/releases/v23.2/v23.2.0-alpha.1.md

@@ -166,7 +166,7 @@ Release Date: September 26, 2023
 - Attempting to [drop a column]({% link v23.2/alter-table.md %}#drop-column) when safe updates are enabled (`sql_safe_updates = on`) now additionally warns users that indexes referencing that column will be automatically dropped. [#108047][#108047]
 - `NOTICE`s are now emitted for each index dropped by an `ALTER TABLE ... DROP COLUMN ...` statement. [#108047][#108047]
 - `SHOW JOBS` now returns times (`created`, `last_run`, and so on) using the `TIMESTAMPTZ` column type instead of the `TIMESTAMP` type, meaning they are now rendered using the session offset. [#108353][#108353]
-- Added a cluster setting `sql.schema.force_declarative_statements` to enable/disable DDL in the [declarative schema changer]({% link v23.2/online-schema-changes.md %}#declarative-schema-changer). [#107815][#107815]
+- Added a cluster setting `sql.schema.force_declarative_statements` to enable/disable DDL in the [declarative schema changer]({% link v23.2/online-schema-changes.md %}). [#107815][#107815]
 - Added the new built-in functions `workload_index_recs()` and `workload_index_recs(TIMESTAMPTZ)`, which return workload level index recommendations (columns of string, each string represent an index recommendation) from statement level index recommendations (as candidates) in `system.statement_statistics`. If the `TIMESTAMPTZ` is given, it will only consider those candidates generated after that `TIMESTAMPTZ` value. [#106525][#106525]
 - Added support for specifying PLpgSQL `IF` statements with `ELSIF` branches. [#108211][#108211]
 - The admin API database details endpoint now returns authoritative range statistics. [#108037][#108037]

src/current/_includes/releases/v23.2/v23.2.0-alpha.6.md

@@ -40,7 +40,7 @@ Release Date: November 7, 2023
 
 <h3 id="v23-2-0-alpha-7-performance-improvements">Performance improvements</h3>
 
-- Addressed a performance regression that can happen when the declarative [schema changer](../v23.2/online-schema-changes.html#declarative-schema-changer) is used to create an index with a concurrent workload. [#113725][#113725]
+- Addressed a performance regression that can happen when the declarative [schema changer](../v23.2/online-schema-changes.html) is used to create an index with a concurrent workload. [#113725][#113725]
 
 <h3 id="v23-2-0-alpha-6-contributors">Contributors</h3>
 

src/current/_includes/releases/v23.2/v23.2.7.md

@@ -36,12 +36,12 @@ Release Date: July 2, 2024
 
 - Fixed a bug where the [`ALTER TABLE ... ALTER PRIMARY KEY`]({% link v23.2/alter-table.md %}#alter-primary-key) command could hang for a table if its indexes are referred to by views or functions using the `force syntax` syntax. [#124569][#124569]
 - Fixed a bug where the [`SHOW TYPES`]({% link v23.2/show-types.md %}) command omitted user-defined composite types. This bug was introduced in v23.1. [#124816][#124816]
-- Fixed a bug where if a column name that contains UTF-8 characters is referenced in the `STORING()` clause of the [`CREATE INDEX`]({% link v23.2/create-index.md %}) command, the [declarative schema changer]({% link v23.2/online-schema-changes.md %}#declarative-schema-changer) cannot detect whether the column is already handled by an existing index. [#125211][#125211]
-- Fixed a bug where the [declarative schema changer]({% link v23.2/online-schema-changes.md %}#declarative-schema-changer) erroneously includes virtual columns that are referenced in the `STORING()` clause of the [`CREATE INDEX`]({% link v23.2/create-index.md %}) command. [#125211][#125211]
+- Fixed a bug where if a column name that contains UTF-8 characters is referenced in the `STORING()` clause of the [`CREATE INDEX`]({% link v23.2/create-index.md %}) command, the [declarative schema changer]({% link v23.2/online-schema-changes.md %}) cannot detect whether the column is already handled by an existing index. [#125211][#125211]
+- Fixed a bug where the [declarative schema changer]({% link v23.2/online-schema-changes.md %}) erroneously includes virtual columns that are referenced in the `STORING()` clause of the [`CREATE INDEX`]({% link v23.2/create-index.md %}) command. [#125211][#125211]
 - Fixed a bug introduced in v20.2, where a change to a user-defined type could cause queries against tables using that type to fail with the error like `histogram.go: span must be fully contained in the bucket`. This bug could occur if the change was from an [`ALTER TABLE`]({% link v23.2/alter-table.md %}) command or from an [`ALTER DATABASE ... ADD REGION`]({% link v23.2/alter-database.md %}) or [`ALTER DATABASE ... DROP REGION`]({% link v23.2/alter-database.md %}) command, which implicitly change the non-public `crdb_internal_region` type. [#124853][#124853]
 - Fixed a bug where telemetry logs could emit the same statement fingerprint ID for different SQL statements. [#125043][#125043]
 - Fixed a bug where adding a column with a default value of an empty array could fail. [#125326][#125326]
-- Fixed a bug where the [declarative schema changer]({% link v23.2/online-schema-changes.md %}#declarative-schema-changer) could erroneously succeed despite a violation of an `ALTER TABLE ... ADD CONSTRAINT UNIQUE` constraint. Now such a violation results in an error message with the error code `42601`. [#125418][#125418]
+- Fixed a bug where the [declarative schema changer]({% link v23.2/online-schema-changes.md %}) could erroneously succeed despite a violation of an `ALTER TABLE ... ADD CONSTRAINT UNIQUE` constraint. Now such a violation results in an error message with the error code `42601`. [#125418][#125418]
 - Fixed a [changefeed]({% link v23.2/create-and-configure-changefeeds.md %}) panic in v24.1, v23.2, and v23.1 when the [cluster setting]({% link v23.2/cluster-settings.md %}) `changefeed.aggregator.flush_jitter` [cluster setting]({% link v23.2/cluster-settings.md %}) is configured and a changefeed's [`min_checkpoint_frequency`]({% link v23.2/create-changefeed.md %}#min-checkpoint-frequency) option is set to zero. [#125469][#125469]
 - Fixed a bug where the public schema was erroneously created with its owner set to the `admin` role instead of the database owner. Ownership  of the public schema can be altered after the schema is created. [#125535][#125535]
 - Fixed a bug introduced in v23.2.0 where inserting rows into a [`REGIONAL BY ROW` table]({% link v23.2/table-localities.md %}#regional-by-row-tables) could cause an internal error if the source was a `VALUES` clause with a single row and at least one boolean expression. [#126208][#126208]