MDEV-17011 “condition_pushdown_for_derived” optimization not used when

using INSERT INTO This patch allows condition pushdown into a materialized derived / view when this table is used in INSERT SELECT, multi-table UPDATE and multi-table DELETE.
MariaDB · Aug 18, 2018 · 862a977 · 862a977
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commit 862a977
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Showing 3 changed files with 188 additions and 2 deletions.
diff --git a/mysql-test/r/derived_cond_pushdown.result b/mysql-test/r/derived_cond_pushdown.result
@@ -9874,3 +9874,146 @@ SELECT a FROM (SELECT "aa" a) t WHERE f1(t.a, (SELECT MAX('aa') FROM DUAL LIMIT
 a
 aa
 DROP FUNCTION f1;
+#
+# MDEV-17011: condition pushdown into materialized derived used
+#             in INSERT SELECT, multi-table UPDATE and DELETE
+#
+CREATE TABLE t1 (a int ,b int) ENGINE=MyISAM;
+INSERT INTO t1 VALUES
+(1, 1), (1, 2), (2, 1), (2, 2), (3,1), (3,3), (4,2);
+CREATE TABLE t2 (a int) ENGINE MYISAM;
+INSERT INTO t2 VALUES
+(3), (7), (1), (4), (1);
+CREATE TABLE t3 (a int, b int) ENGINE MYISAM;
+EXPLAIN FORMAT=JSON INSERT INTO t3
+SELECT * FROM (SELECT a, count(*) as c FROM t1 GROUP BY a) t WHERE a<=2;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "<derived2>",
+      "access_type": "ALL",
+      "rows": 7,
+      "filtered": 100,
+      "attached_condition": "t.a <= 2",
+      "materialized": {
+        "query_block": {
+          "select_id": 2,
+          "filesort": {
+            "sort_key": "t1.a",
+            "temporary_table": {
+              "table": {
+                "table_name": "t1",
+                "access_type": "ALL",
+                "rows": 7,
+                "filtered": 100,
+                "attached_condition": "t1.a <= 2"
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+INSERT INTO t3
+SELECT * FROM (SELECT a, count(*) as c FROM t1 GROUP BY a) t WHERE a<=2;
+SELECT * FROM t3;
+a	b
+1	2
+2	2
+EXPLAIN FORMAT=JSON UPDATE t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t SET t2.a=t.c+10
+WHERE t2.a= t.c and t.a>=3;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t2",
+      "access_type": "ALL",
+      "rows": 5,
+      "filtered": 100,
+      "attached_condition": "t2.a is not null"
+    },
+    "table": {
+      "table_name": "<derived2>",
+      "access_type": "ref",
+      "possible_keys": ["key0"],
+      "key": "key0",
+      "key_length": "8",
+      "used_key_parts": ["c"],
+      "ref": ["test.t2.a"],
+      "rows": 2,
+      "filtered": 100,
+      "attached_condition": "t2.a = t.c and t.a >= 3",
+      "materialized": {
+        "query_block": {
+          "select_id": 2,
+          "filesort": {
+            "sort_key": "t1.a",
+            "temporary_table": {
+              "table": {
+                "table_name": "t1",
+                "access_type": "ALL",
+                "rows": 7,
+                "filtered": 100,
+                "attached_condition": "t1.a >= 3"
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
+UPDATE t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t SET t2.a=t.c+10
+WHERE t2.a= t.c and t.a>=3;
+SELECT * FROM t2;
+a
+3
+7
+11
+4
+11
+EXPLAIN FORMAT=JSON DELETE t2 FROM t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t
+WHERE t2.a= t.c+9 and t.a=2;
+EXPLAIN
+{
+  "query_block": {
+    "select_id": 1,
+    "table": {
+      "table_name": "t2",
+      "access_type": "ALL",
+      "rows": 5,
+      "filtered": 100
+    },
+    "table": {
+      "table_name": "<derived2>",
+      "access_type": "ALL",
+      "rows": 7,
+      "filtered": 100,
+      "attached_condition": "t.a = 2 and t2.a = t.c + 9",
+      "materialized": {
+        "query_block": {
+          "select_id": 2,
+          "table": {
+            "table_name": "t1",
+            "access_type": "ALL",
+            "rows": 7,
+            "filtered": 100,
+            "attached_condition": "t1.a = 2"
+          }
+        }
+      }
+    }
+  }
+}
+DELETE t2 FROM t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t
+WHERE t2.a= t.c+9 and t.a=2;
+SELECT * FROM t2;
+a
+3
+7
+4
+DROP TABLE t1,t2,t3;
diff --git a/mysql-test/t/derived_cond_pushdown.test b/mysql-test/t/derived_cond_pushdown.test
@@ -1920,3 +1920,47 @@ END;$$
 DELIMITER ;$$
 SELECT a FROM (SELECT "aa" a) t WHERE f1(t.a, (SELECT MAX('aa') FROM DUAL LIMIT 1));
 DROP FUNCTION f1;
+
+--echo #
+--echo # MDEV-17011: condition pushdown into materialized derived used
+--echo #             in INSERT SELECT, multi-table UPDATE and DELETE
+--echo #
+
+CREATE TABLE t1 (a int ,b int) ENGINE=MyISAM;
+INSERT INTO t1 VALUES
+  (1, 1), (1, 2), (2, 1), (2, 2), (3,1), (3,3), (4,2);
+
+CREATE TABLE t2 (a int) ENGINE MYISAM;
+INSERT INTO t2 VALUES
+  (3), (7), (1), (4), (1);
+
+CREATE TABLE t3 (a int, b int) ENGINE MYISAM;
+
+let $q1=
+INSERT INTO t3
+SELECT * FROM (SELECT a, count(*) as c FROM t1 GROUP BY a) t WHERE a<=2;
+
+eval EXPLAIN FORMAT=JSON $q1;
+eval $q1;
+
+SELECT * FROM t3;
+
+let $q2=
+UPDATE t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t SET t2.a=t.c+10
+  WHERE t2.a= t.c and t.a>=3;
+
+eval EXPLAIN FORMAT=JSON $q2;
+eval $q2;
+
+SELECT * FROM t2;
+
+let $q3=
+DELETE t2 FROM t2, (SELECT a, count(*) as c FROM t1 GROUP BY a) t
+  WHERE t2.a= t.c+9 and t.a=2;
+
+eval EXPLAIN FORMAT=JSON $q3;
+eval $q3;
+
+SELECT * FROM t2;
+
+DROP TABLE t1,t2,t3;
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
@@ -1375,8 +1375,7 @@ JOIN::optimize_inner()
     DBUG_RETURN(1);
   }
 
-  if (thd->lex->sql_command == SQLCOM_SELECT &&
-      optimizer_flag(thd, OPTIMIZER_SWITCH_COND_PUSHDOWN_FOR_DERIVED))
+  if (optimizer_flag(thd, OPTIMIZER_SWITCH_COND_PUSHDOWN_FOR_DERIVED))
   {
     TABLE_LIST *tbl;
     List_iterator_fast<TABLE_LIST> li(select_lex->leaf_tables);