[BugFix] Don't update datacache metrics after cache select (backport #…

…51764) (#51810)

Co-authored-by: Smith Cruise <[email protected]>

fe/fe-core/src/main/java/com/starrocks/datacache/DataCacheSelectExecutor.java

@@ -84,8 +84,10 @@ public static DataCacheSelectMetrics cacheSelect(DataCacheSelectStatement statem
         connectContext.setSessionVariable(sessionVariableBackup);
 
         Preconditions.checkNotNull(metrics, "Failed to retrieve cache select metrics");
+        // Don't update datacache metrics after cache select, because of datacache instance still not unified.
+        // Here update will display wrong metrics in show backends/compute nodes
         // update backend's datacache metrics after cache select
-        updateBackendDataCacheMetrics(metrics);
+        // updateBackendDataCacheMetrics(metrics);
         return metrics;
     }