add tidb usage limitation with stats

YangKeao · YangKeao · commit bea518ccc2f3 · 2025-04-22T16:21:20.000+08:00
Signed-off-by: Yang Keao &lt;yangkeao@chunibyo.icu&gt;
diff --git a/information-schema/information-schema-tidb-index-usage.md b/information-schema/information-schema-tidb-index-usage.md
@@ -101,6 +101,7 @@ The output is as follows:
 
 - The data in the `TIDB_INDEX_USAGE` table might be delayed by up to 5 minutes.
 - After TiDB restarts, the data in the `TIDB_INDEX_USAGE` table is cleared.
+- Index usage is only recorded if the table has valid statistics.
 
 ## Read more
 
