Optimize SQL Queries to Improve Dashboard Scalability and Performance

[db-will]

Bug Report

What did you do?

When a TiDB cluster grows large, a significant number of SQL statements, slow queries, and other resource data are retrieved from the database for display. However, if an SQL query takes too long, a configured timeout may prevent the dashboard from displaying any information. Currently, dashboard won't be able to show anything and report errors.

To better support large-scale TiDB clusters, the TiDB Dashboard should implement features like pagination, optimize indexing (e.g., for ORDER BY operations), and adopt other techniques to enhance performance and usability.

What did you expect to see?

TiDB Dashboard can scale to support display sql statements, slow queries and potentially other resources.

What did you see instead?

TiDB Dashboard show errors for 504.

What version of TiDB Dashboard are you using (./tidb-dashboard --version)?

v8.1.1