[BugFix] Guard sync MV fallback with isSyncMVQuery() hint check

Move the getMaterializedViewIndex() fallback from resolveTable() into
visitTable(), gated by TableRelation.isSyncMVQuery(). This avoids the
expensive linear scan for non-existent table names that are not sync MV
queries, matching the pattern used in QueryAnalyzer.

Also add missing test_table cleanup in PlannerMetaLockerTest.afterEach()
to prevent test pollution.

Signed-off-by: rickxz <herick.victor.rodrigues@hotmail.com>

Author: rickxz

fe/fe-core/src/main/java/com/starrocks/sql/analyzer/PlannerMetaLocker.java

@@ -176,24 +176,36 @@ private static Pair<Database, Table> resolveTable(ConnectContext session, TableN
 
         Table table = metadataMgr.getTable(session, catalogName, dbName, tbName);
         if (table == null) {
-            // Fallback: Sync MV names are index names, not table names.
-            // When querying via [_SYNC_MV_] hint, we need to resolve through the
-            // materialized index to find the base table and its database.
-            // This ensures the database is registered in currentSqlDbIds for
-            // resource group classifier matching.
-            Pair<Table, MaterializedIndexMeta> mvIndex =
-                    GlobalStateMgr.getCurrentState().getLocalMetastore()
-                            .getMaterializedViewIndex(dbName, tbName);
-            if (mvIndex != null) {
-                table = mvIndex.first;
-            }
+            return null;
         }
 
-        if (table == null) {
+        return new Pair<>(db, table);
+    }
+
+    private static Pair<Database, Table> resolveSyncMV(ConnectContext session, TableName tableName) {
+        String dbName = tableName.getDb();
+        String tbName = tableName.getTbl();
+
+        if (Strings.isNullOrEmpty(dbName)) {
+            dbName = session.getDatabase();
+        }
+        if (Strings.isNullOrEmpty(dbName) || Strings.isNullOrEmpty(tbName)) {
             return null;
         }
 
-        return new Pair<>(db, table);
+        Pair<Table, MaterializedIndexMeta> mvIndex =
+                GlobalStateMgr.getCurrentState().getLocalMetastore()
+                        .getMaterializedViewIndex(dbName, tbName);
+        if (mvIndex == null) {
+            return null;
+        }
+
+        Database db = GlobalStateMgr.getCurrentState().getLocalMetastore().getDb(dbName);
+        if (db == null) {
+            return null;
+        }
+
+        return new Pair<>(db, mvIndex.first);
     }
 
     private static class TableCollector extends AstTraverser<Void, Void> {
@@ -262,6 +274,9 @@ public Void visitAlterMaterializedViewStatement(AlterMaterializedViewStmt statem
         @Override
         public Void visitTable(TableRelation node, Void context) {
             Pair<Database, Table> dbAndTable = resolveTable(session, node.getName());
+            if (dbAndTable == null && node.isSyncMVQuery()) {
+                dbAndTable = resolveSyncMV(session, node.getName());
+            }
             put(dbAndTable);
             return null;
         }

fe/fe-core/src/test/java/com/starrocks/sql/analyzer/PlannerMetaLockerTest.java

@@ -58,6 +58,10 @@ public void afterEach() throws Exception {
             starRocksAssert.dropMaterializedView("test_mv");
         } catch (Exception ignored) {
         }
+        try {
+            starRocksAssert.dropTable("test_table");
+        } catch (Exception ignored) {
+        }
         try {
             DDLStmtExecutor.execute(
                     UtFrameUtils.parseStmtWithNewParser("drop resource group test_rg", connectContext),