Add support for refreshing views in memory connector

Author: Praveen2112

core/trino-main/src/main/java/io/trino/execution/RefreshViewTask.java

@@ -104,7 +104,7 @@ public ListenableFuture<Void> execute(
 
         Session viewSession = stateMachine.getSession();
         if (!viewDefinition.isRunAsInvoker()) {
-            checkArgument(viewDefinition.getRunAsIdentity().isEmpty(), "View owner detail is missing");
+            checkArgument(viewDefinition.getRunAsIdentity().isPresent(), "View owner detail is missing");
             viewSession = viewSession.createViewSession(viewDefinition.getCatalog(), viewDefinition.getSchema(), viewDefinition.getRunAsIdentity().get(), viewDefinition.getPath());
         }
 

core/trino-main/src/main/java/io/trino/tracing/TracingConnectorMetadata.java

@@ -789,6 +789,15 @@ public void renameView(ConnectorSession session, SchemaTableName source, SchemaT
         }
     }
 
+    @Override
+    public void refreshView(ConnectorSession session, SchemaTableName viewName, ConnectorViewDefinition definition)
+    {
+        Span span = startSpan("refreshView", viewName);
+        try (var _ = scopedSpan(span)) {
+            delegate.refreshView(session, viewName, definition);
+        }
+    }
+
     @Override
     public void setViewAuthorization(ConnectorSession session, SchemaTableName viewName, TrinoPrincipal principal)
     {

plugin/trino-memory/src/main/java/io/trino/plugin/memory/MemoryMetadata.java

@@ -555,6 +555,18 @@ public synchronized void renameView(ConnectorSession session, SchemaTableName vi
         views.put(newViewName, views.remove(viewName));
     }
 
+    @Override
+    public synchronized void refreshView(ConnectorSession session, SchemaTableName viewName, ConnectorViewDefinition viewDefinition)
+    {
+        checkSchemaExists(viewName.getSchemaName());
+
+        if (!tableIds.containsKey(viewName)) {
+            throw new TrinoException(NOT_FOUND, "View not found: " + viewName);
+        }
+
+        views.replace(viewName, viewDefinition);
+    }
+
     @Override
     public synchronized void dropView(ConnectorSession session, SchemaTableName viewName)
     {

testing/trino-testing/src/main/java/io/trino/testing/BaseConnectorTest.java

@@ -139,6 +139,7 @@
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_MULTI_STATEMENT_WRITES;
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_NEGATIVE_DATE;
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_NOT_NULL_CONSTRAINT;
+import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_REFRESH_VIEW;
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_RENAME_COLUMN;
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_RENAME_FIELD;
 import static io.trino.testing.TestingConnectorBehavior.SUPPORTS_RENAME_MATERIALIZED_VIEW;
@@ -988,6 +989,46 @@ public void testView()
                 .doesNotContain(testView);
     }
 
+    @Test
+    public void testRefreshView()
+    {
+        if (!hasBehavior(SUPPORTS_REFRESH_VIEW)) {
+            if (hasBehavior(SUPPORTS_CREATE_VIEW)) {
+                try (TestView testView = new TestView(getQueryRunner()::execute, "test_view", " SELECT * FROM nation")) {
+                    assertQueryFails("ALTER VIEW %s REFRESH".formatted(testView.getName()), "This connector does not refreshing views");
+                }
+            }
+            else {
+                assertQueryFails("CREATE VIEW sample_view AS SELECT * FROM nation", "This connector does not support creating views");
+            }
+            return;
+        }
+
+        if (!hasBehavior(SUPPORTS_CREATE_TABLE) && !hasBehavior(SUPPORTS_ADD_COLUMN)) {
+            throw new AssertionError("Cannot test ALTER VIEW REFRESH without CREATE TABLE, the test needs to be implemented in a connector-specific way");
+        }
+
+        try (TestTable table = new TestTable(getQueryRunner()::execute, "test_table", "(id BIGINT, column_to_dropped BIGINT)", ImmutableList.of("1, 2"));
+                TestView view = new TestView(getQueryRunner()::execute, "test_view", " SELECT * FROM %s".formatted(table.getName()))) {
+            assertQuery("SELECT * FROM %s".formatted(view.getName()), "VALUES (1, 2)");
+
+            assertUpdate("ALTER TABLE %s ADD COLUMN new_column BIGINT".formatted(table.getName()));
+            assertQueryFails(
+                    "SELECT * FROM %s".formatted(view.getName()),
+                    ".*is stale or in invalid state: stored view column count \\(2\\) does not match column count derived from the view query analysis \\(3\\)");
+
+            assertUpdate("ALTER VIEW %s REFRESH".formatted(view.getName()));
+            assertQuery("SELECT * FROM %s".formatted(view.getName()), "VALUES (1, 2, null)");
+
+            assertUpdate("ALTER TABLE %s RENAME COLUMN new_column TO renamed_column".formatted(table.getName()));
+            assertQueryFails(
+                    "SELECT * FROM %s".formatted(view.getName()),
+                    ".*is stale or in invalid state: column \\[renamed_column] of type bigint projected from query view at position 2 has a different name from column \\[new_column] of type bigint stored in view definition");
+            assertUpdate("ALTER VIEW %s REFRESH".formatted(view.getName()));
+            assertQuery("SELECT * FROM %s".formatted(view.getName()), "VALUES (1, 2, null)");
+        }
+    }
+
     @Test
     public void testCreateViewSchemaNotFound()
     {

testing/trino-testing/src/main/java/io/trino/testing/TestingConnectorBehavior.java

@@ -104,6 +104,7 @@ public enum TestingConnectorBehavior
     SUPPORTS_CREATE_VIEW,
     SUPPORTS_COMMENT_ON_VIEW(and(SUPPORTS_CREATE_VIEW, SUPPORTS_COMMENT_ON_TABLE)),
     SUPPORTS_COMMENT_ON_VIEW_COLUMN(SUPPORTS_COMMENT_ON_VIEW),
+    SUPPORTS_REFRESH_VIEW(SUPPORTS_CREATE_VIEW),
 
     SUPPORTS_CREATE_MATERIALIZED_VIEW,
     SUPPORTS_CREATE_MATERIALIZED_VIEW_GRACE_PERIOD(SUPPORTS_CREATE_MATERIALIZED_VIEW),