Bug#36130806 EstimateDeleteRowsCost() Assertion failed: val >= 0.0 || val == kUnknownCost

This commit ensures that we set the cost of AccessPath objects of type
MATERIALIZED_TABLE_FUNCTION. That cost can then be used as input for
cost calculations higher up in the AccessPath tree.

Change-Id: If11f0df40a1cc3b7cb360f1c88f5b7449c07a8d2

Author: Jan Wedvik

mysql-test/suite/json/r/json_table.result

@@ -2196,3 +2196,26 @@ SELECT * FROM JSON_TABLE('[1, 2]', '$' COLUMNS (
 #
 SELECT 1 FROM JSON_TABLE(ROW(1, 2), '$' COLUMNS (o FOR ORDINALITY)) AS jt;
 ERROR 21000: Operand should contain 1 column(s)
+#
+# Bug#36130806 EstimateDeleteRowsCost()
+# Assertion failed: val >= 0.0 || val == kUnknownCost
+#
+CREATE TABLE t (c0 INT PRIMARY KEY);
+INSERT INTO t VALUES (1),(2);
+ANALYZE TABLE t;
+Table	Op	Msg_type	Msg_text
+test.t	analyze	status	OK
+EXPLAIN FORMAT=TREE DELETE FROM t WHERE EXISTS
+(
+SELECT a FROM json_table('[{"a":"3"}]','$[0].a'
+  COLUMNS( a FOR ORDINALITY)
+) as q
+);
+EXPLAIN
+-> Delete from t (buffered)  (rows=2)
+    -> Nested loop inner join  (rows=2)
+        -> Limit: 1 row(s)  (rows=1)
+            -> Materialize table function  (rows=2)
+        -> Table scan on t  (rows=2)
+
+DROP TABLE t;

mysql-test/suite/json/t/json_table.test

@@ -1,3 +1,4 @@
+--source include/elide_costs.inc
 # For stable statistics
 --source include/have_innodb_16k.inc
 --echo # 
@@ -1533,3 +1534,26 @@ SELECT * FROM JSON_TABLE('[1, 2]', '$' COLUMNS (
 --echo #
 --error ER_OPERAND_COLUMNS
 SELECT 1 FROM JSON_TABLE(ROW(1, 2), '$' COLUMNS (o FOR ORDINALITY)) AS jt;
+
+--echo #
+--echo # Bug#36130806 EstimateDeleteRowsCost()
+--echo # Assertion failed: val >= 0.0 || val == kUnknownCost
+--echo #
+
+CREATE TABLE t (c0 INT PRIMARY KEY);
+
+INSERT INTO t VALUES (1),(2);
+
+ANALYZE TABLE t;
+
+# Do a 'delete' using a subquery with a table function.
+--replace_regex $elide_costs
+--skip_if_hypergraph  # Depends on the query plan.
+EXPLAIN FORMAT=TREE DELETE FROM t WHERE EXISTS
+(
+  SELECT a FROM json_table('[{"a":"3"}]','$[0].a'
+  COLUMNS( a FOR ORDINALITY)
+ ) as q
+);
+
+DROP TABLE t;

sql/sql_executor.cc

@@ -1765,6 +1765,8 @@ static AccessPath *GetTableAccessPath(THD *thd, QEP_TAB *qep_tab,
     table_path = NewMaterializedTableFunctionAccessPath(
         thd, qep_tab->table(), qep_tab->table_ref->table_function,
         qep_tab->access_path());
+
+    CopyBasicProperties(*qep_tab->access_path(), table_path);
   } else if (qep_tab->materialize_table == QEP_TAB::MATERIALIZE_SEMIJOIN) {
     Semijoin_mat_exec *sjm = qep_tab->sj_mat_exec();