lcspinter commented on code in PR #3552:
URL: https://github.com/apache/hive/pull/3552#discussion_r967065389


##########
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/views/HiveMaterializedViewUtils.java:
##########
@@ -160,11 +181,79 @@ public static Boolean isOutdatedMaterializedView(
     return false;
   }
 
+  private static Boolean isOutdatedMaterializedView(
+          MaterializationSnapshot snapshot, Hive db,
+          Set<TableName> tablesUsed, Table materializedViewTable) throws 
HiveException {
+    List<String> tablesUsedNames = tablesUsed.stream()
+        .map(tableName -> TableName.getDbTable(tableName.getDb(), 
tableName.getTable()))
+        .collect(Collectors.toList());
+
+    Map<String, String> snapshotMap = snapshot.getTableSnapshots();
+    if (snapshotMap == null || snapshotMap.isEmpty()) {
+      LOG.debug("Materialized view " + 
materializedViewTable.getFullyQualifiedName() +
+              " ignored for rewriting as we could not obtain current snapshot 
ids");
+      return null;
+    }
+
+    Set<String> storedTablesUsed = 
materializedViewTable.getMVMetadata().getSourceTableFullNames();
+    for (String fullyQualifiedTableName : tablesUsedNames) {
+      // Note. If the materialized view does not contain a table that is 
contained in the query,
+      // we do not need to check whether that specific table is outdated or 
not. If a rewriting
+      // is produced in those cases, it is because that additional table is 
joined with the
+      // existing tables with an append-columns only join, i.e., PK-FK + not 
null.
+      if (!storedTablesUsed.contains(fullyQualifiedTableName)) {
+        continue;
+      }
+
+      Table table = db.getTable(fullyQualifiedTableName);
+      if (table.getStorageHandler() == null) {
+        LOG.debug("Materialized view {} ignored for rewriting as we could not 
storage handler of table {}",
+                materializedViewTable.getFullyQualifiedName(), 
fullyQualifiedTableName);
+        return null;
+      }
+      String currentTableSnapshot = 
table.getStorageHandler().getCurrentSnapshotId(table);
+      if (isBlank(currentTableSnapshot)) {

Review Comment:
   Thanks! I really like this new change



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