Update descriptions for tidb_schema_cache_size (#18101)

releases/release-8.0.0.md

@@ -37,12 +37,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
   </tr>
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     <td>Enhance the stability of caching the schema information when there is a massive number of tables (experimental)</td>
-    <td>SaaS companies using TiDB as the system of record for their multi-tenant applications often need to store a substantial number of tables. In previous versions, handling table counts in the order of a million or more was feasible, but it had the potential to degrade the overall user experience. TiDB v8.0.0 improves the situation with the following enhancements:
-  <ul>
-    <li>Introduce a new <a href="https://docs.pingcap.com/tidb/v8.0/system-variables#tidb_schema_cache_size-new-in-v800">schema information caching system</a>, incorporating a lazy-loading Least Recently Used (LRU) cache for table metadata and more efficiently managing schema version changes.</li>
-    <li>Implement a <a href="https://docs.pingcap.com/tidb/v8.0/system-variables#tidb_enable_auto_analyze_priority_queue-new-in-v800">priority queue</a> for <code>auto analyze</code>, making the process less rigid and enhancing stability across a wider array of tables.</li>
-  </ul>
-    </td>
+    <td>SaaS companies using TiDB as the system of record for their multi-tenant applications often need to store a substantial number of tables. In previous versions, handling table counts in the order of a million or more was feasible, but it had the potential to degrade the overall user experience. TiDB v8.0.0 improves the situation by implementing a <a href="https://docs.pingcap.com/tidb/v8.0/system-variables#tidb_enable_auto_analyze_priority_queue-new-in-v800">priority queue</a> for <code>auto analyze</code>, making the process less rigid and enhancing stability across a wider array of tables.</td>
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     <td rowspan="1">DB Operations and Observability</td>
@@ -146,16 +141,6 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
 
     For more information, see [documentation](/system-variables.md#tidb_low_resolution_tso_update_interval-new-in-v800).
 
-### Reliability
-
-* Support caching required schema information according to the LRU algorithm to reduce memory consumption on the TiDB server (experimental) [#50959](https://github.com/pingcap/tidb/issues/50959) @[gmhdbjd](https://github.com/gmhdbjd)
-
-    Before v8.0.0, each TiDB node caches the schema information of all tables. In scenarios with hundreds of thousands of tables, just caching these table schemas could consume a significant amount of memory.
-
-    Starting from v8.0.0, TiDB introduces the system variable [`tidb_schema_cache_size`](/system-variables.md#tidb_schema_cache_size-new-in-v800), which enables you to set an upper limit for caching schema information, thereby preventing excessive memory usage. When you enable this feature, TiDB uses the Least Recently Used (LRU) algorithm to cache the required tables, effectively reducing the memory consumed by the schema information.
-
-    For more information, see [documentation](/system-variables.md#tidb_schema_cache_size-new-in-v800).
-
 ### Availability
 
 * The proxy component TiProxy becomes generally available (GA) [#413](https://github.com/pingcap/tiproxy/issues/413) @[djshow832](https://github.com/djshow832) @[xhebox](https://github.com/xhebox)

releases/release-8.1.0.md

@@ -45,12 +45,7 @@ Compared with the previous LTS 7.5.0, 8.1.0 includes new features, improvements,
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   <tr>
     <td>Enhance the stability of caching the schema information when there is a massive number of tables (experimental, introduced in v8.0.0)</td>
-    <td>SaaS companies using TiDB as the system of record for their multi-tenant applications often need to store a substantial number of tables. In previous versions, handling table counts in the order of a million or more was feasible, but it had the potential to degrade the overall user experience. TiDB v8.0.0 improves the situation with the following enhancements:
-      <ul>
-      <li>Introduce a new <a href="https://docs.pingcap.com/tidb/v8.1/system-variables#tidb_schema_cache_size-new-in-v800">schema information caching system</a>, which provides a cache strategy based on the Least Recently Used (LRU) algorithm for table metadata. It prioritizes storing the metadata of frequently accessed tables in the cache, thereby reducing memory usage in scenarios with a large number of tables.</li>
-      <li>Implement a <a href="https://docs.pingcap.com/tidb/v8.1/system-variables#tidb_enable_auto_analyze_priority_queue-new-in-v800">priority queue</a> for <code>auto analyze</code>, making the process less rigid and enhancing stability across a wider array of tables.</li>
-      </ul>
-    </td>
+    <td>SaaS companies using TiDB as the system of record for their multi-tenant applications often need to store a substantial number of tables. In previous versions, handling table counts in the order of a million or more was feasible, but it had the potential to degrade the overall user experience. TiDB v8.0.0 improves the situation by implementing a <a href="https://docs.pingcap.com/tidb/v8.1/system-variables#tidb_enable_auto_analyze_priority_queue-new-in-v800">priority queue</a> for <code>auto analyze</code>, making the process less rigid and enhancing stability across a wider array of tables.</td>
   </tr>
   <tr>
     <td rowspan="5">Reliability and availability</td>

system-variables.md

@@ -5072,7 +5072,7 @@ SHOW WARNINGS;
 
 > **Warning:**
 >
-> This feature is experimental. It is not recommended that you use it in the production environment. This feature might be changed or removed without prior notice. If you find a bug, you can report an [issue](https://github.com/pingcap/tidb/issues) on GitHub.
+> The feature controlled by this variable is not yet effective in the current TiDB version. Do not change the default value.
 
 - Scope: GLOBAL
 - Persists to cluster: Yes