Update information-schema slow query & Statement.md (#12482)

information-schema/information-schema-slow-query.md

@@ -7,6 +7,14 @@ summary: Learn the `SLOW_QUERY` information_schema table.
 
 The `SLOW_QUERY` table provides the slow query information of the current node, which is the parsing result of the TiDB slow log file. The column names in the table are corresponding to the field names in the slow log.
 
+<CustomContent platform="tidb-cloud">
+
+> **Note:**
+>
+> The `SLOW_QUERY` table is unavailable for [Serverless Tier clusters](/tidb-cloud/select-cluster-tier.md#serverless-tier-beta).
+
+</CustomContent>
+
 <CustomContent platform="tidb">
 
 For how to use this table to identify problematic statements and improve query performance, see [Slow Query Log Document](/identify-slow-queries.md).

statement-summary-tables.md

@@ -16,6 +16,14 @@ Therefore, starting from v4.0.0-rc.1, TiDB provides system tables in `informatio
 - [`cluster_statements_summary_history`](#statements_summary_evicted)
 - [`statements_summary_evicted`](#statements_summary_evicted)
 
+<CustomContent platform="tidb-cloud">
+
+> **Note:**
+>
+> The following tables are unavailable for [Serverless Tier clusters](/tidb-cloud/select-cluster-tier.md#serverless-tier-beta): `statements_summary`, `statements_summary_history`, `cluster_statements_summary`, and `cluster_statements_summary_history`.
+
+</CustomContent>
+
 This document details these tables and introduces how to use them to troubleshoot SQL performance issues.
 
 ## `statements_summary`

tidb-cloud/serverless-tier-limitations.md

@@ -24,6 +24,10 @@ We are constantly filling in the feature gaps between Serverless Tier and Dedica
 - [Time to live (TTL)](/time-to-live.md) is not available for Serverless Tier clusters currently.
 - The [`FLASHBACK CLUSTER TO TIMESTAMP`](/sql-statements/sql-statement-flashback-to-timestamp.md) syntax is not applicable to TiDB Cloud [Serverless Tier](/tidb-cloud/select-cluster-tier.md#serverless-tier-beta) clusters.
 
+## System tables
+
+- Tables `CLUSTER_SLOW_QUERY`, `SLOW_QUERY`, `CLUSTER_STATEMENTS_SUMMARY`, `CLUSTER_STATEMENTS_SUMMARY_HISTORY`, `STATEMENTS_SUMMARY`, `STATEMENTS_SUMMARY_HISTORY` are not available for Serverless Tier clusters.
+
 ## Transaction
 
 - The total size of a single transaction is set to no more than 10 MB on Serverless Tier during the beta phase.
@@ -42,6 +46,10 @@ We are constantly filling in the feature gaps between Serverless Tier and Dedica
 - [Built-in Monitoring](/tidb-cloud/built-in-monitoring.md) is currently not available for Serverless Tier.
 - [Third-party Monitoring integrations](/tidb-cloud/third-party-monitoring-integrations.md) are currently not available for Serverless Tier.
 
+## Diagnosis
+
+- [SQL Diagnosis](/tidb-cloud/tune-performance.md) is currently not available for Serverless Tier.
+
 ## Stream data
 
 * [Changefeed](/tidb-cloud/changefeed-overview.md) is not supported for Serverless Tier currently.

tidb-cloud/tune-performance.md

@@ -13,6 +13,10 @@ TiDB Cloud provides [Statement Analysis](#statement-analysis), [Slow Query](#slo
 
 - Key Visualizer helps you observe TiDB's data access patterns and data hotspots.
 
+> **Note:**
+>
+> Currently, these three features are unavailable for [Serverless Tier clusters](/tidb-cloud/select-cluster-tier.md#serverless-tier-beta).
+
 ## Statement Analysis
 
 To use the statement analysis, perform the following steps: