[yugabyte#14278] YSQL: Make sure copy function for YbBatchedNestLoop …

…does a deep copy for its fields

Summary:
`_copyYbBatchedNestLoop` in `copyfuncs.c` was doing a shallow copy of its `nl` field. This results in the field having invalid fields when a copy of a `YbBatchedNestLoop` plan is reused over multiple connections. This revision fixes that issue by adding the appropriate copy logic in `_copyYbBatchedNestLoop`.

This revision also fixes a couple glaring cosmetic issues in code relevant to batched nested loop joins.

Test Plan:
./yb_build.sh release --java-test 'org.yb.pgsql.TestPgMisc'

Reviewers: rskannan, amartsinchyk

Reviewed By: amartsinchyk

Differential Revision: https://phabricator.dev.yugabyte.com/D19919

java/yb-pgsql/src/test/java/org/yb/pgsql/TestPgMisc.java

@@ -245,4 +245,36 @@ public void testPgHintPlanExtendedQuery() throws Exception {
       statement.executeUpdate("DROP TABLE test_table;");
     }
   }
+
+  /*
+   * Test to make sure that batched nested loops joins work with extended queries over
+   * multiple invocations.
+   * See issue #14278.
+   */
+  @Test
+  public void testBatchedNestLoopExtendedQuery() throws Exception {
+    try (Statement statement = connection.createStatement()) {
+      statement.executeUpdate("CREATE TABLE test_table1(r1 int, r2 int," +
+                              "PRIMARY KEY(r1 asc))");
+      statement.executeUpdate("CREATE TABLE test_table2(r1 int, r2 int," +
+                              "PRIMARY KEY(r1 asc))");
+
+      String QUERY = "/*+Set(enable_hashjoin off) Set(enable_mergejoin off) " +
+                     "Set(yb_bnl_batch_size 4) Set(enable_seqscan off) " +
+                     "Set(enable_material off)*/ " +
+                     "SELECT * FROM test_table1, test_table2 " +
+                     "WHERE test_table1.r1 = test_table2.r1";
+      PreparedStatement stmt = connection.prepareStatement(QUERY);
+      // Make sure we're always preparing statements at the server
+      com.yugabyte.jdbc.PgStatement pgstmt = (com.yugabyte.jdbc.PgStatement) stmt;
+      pgstmt.setPrepareThreshold(1);
+
+      stmt.executeQuery();
+      stmt.executeQuery();
+      stmt.executeQuery();
+
+      statement.executeUpdate("DROP TABLE test_table1;");
+      statement.executeUpdate("DROP TABLE test_table2;");
+    }
+  }
 }

src/postgres/src/backend/nodes/copyfuncs.c

@@ -893,9 +893,10 @@ _copyYbBatchedNestLoop(const YbBatchedNestLoop *from)
 	YbBatchedNestLoop   *newnode = makeNode(YbBatchedNestLoop);
 
 	/*
-	 * copy NestLoop field
+	 * copy node superclass fields
 	 */
-	COPY_SCALAR_FIELD(nl);
+	CopyJoinFields((const Join *) from, (Join *) newnode);
+	COPY_NODE_FIELD(nl.nestParams);
 
 	/*
 	 * copy remainder of node

src/postgres/src/backend/optimizer/plan/planner.c

@@ -627,7 +627,7 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 	root->inhTargetKind = INHKIND_NONE;
 	root->hasRecursion = hasRecursion;
 	root->yb_curbatchedrelids = parent_root ? parent_root->yb_curbatchedrelids
-											: false;
+											: NULL;
 	root->yb_cur_batch_no = -1;
 	if (hasRecursion)
 		root->wt_param_id = assign_special_exec_param(root);

src/postgres/src/include/executor/nodeYbBatchedNestloop.h

@@ -15,7 +15,7 @@
  * or implied.  See the License for the specific language governing permissions and limitations
  * under the License.
  *
- * src/postgres/src/include/executor/nodeYbBatchedNestLoop.h
+ * src/postgres/src/include/executor/nodeYbBatchedNestloop.h
  *
  *-------------------------------------------------------------------------
  */