!5828 物化视图功能增强，补齐功能，包括支持删除操作

Merge pull request !5828 from TinyBag/matview

src/include/nodes/nodes.h

@@ -589,6 +589,8 @@ typedef enum NodeTag {
     T_ShrinkStmt,
     T_VariableMultiSetStmt,
     T_CursorExpression,
+    T_CreateMatViewLogStmt,
+    T_DropMatViewLogStmt,
     /*
      * TAGS FOR PARSE TREE NODES (parsenodes.h)
      * note: TAGS FOR PARSE TREE NODES (parsenodes.h) can no longer place new tags, 

src/include/nodes/parsenodes.h

@@ -2188,6 +2188,26 @@ typedef struct RefreshMatViewStmt
    RangeVar   *relation;       /* relation to insert into */
 } RefreshMatViewStmt;
 
+/* ----------------------
+ *     CREATE MATERIALIZED VIEW LOG Statement
+ * ----------------------
+ */
+typedef struct CreateMatViewLogStmt
+{
+   NodeTag     type;
+   RangeVar*   relation;       /* relation to create matview log for */
+} CreateMatViewLogStmt;
+
+/* ----------------------
+ *     DROP MATERIALIZED VIEW LOG Statement
+ * ----------------------
+ */
+typedef struct DropMatViewLogStmt
+{
+   NodeTag     type;
+   RangeVar*   relation;       /* relation to drop matview log from */
+} DropMatViewLogStmt;
+
 /* ----------------------
  * Checkpoint Statement
  * ----------------------