# 使用
#### 语法格式
- 创建增量物化视图
  ```
  CREATE INCREMENTAL MATERIALIZED VIEW [ view_name ] AS { query_block };
  ```
  

- 全量刷新物化视图
  ```
  REFRESH MATERIALIZED VIEW [ view_name ];
  ```
  

- 增量刷新物化视图
  ```
  REFRESH INCREMENTAL MATERIALIZED VIEW [ view_name ];
  ```
  

- 删除物化视图
  ```
  DROP MATERIALIZED VIEW [ view_name ];
  ```
  

- 查询物化视图
  ```
  SELECT * FROM [ view_name ];
  ```
  
 
#### 示例
```
-- 准备数据
CREATE TABLE t1(c1 int, c2 int);
INSERT INTO t1 VALUES(1, 1);
INSERT INTO t1 VALUES(2, 2);
-- 创建增量物化视图
openGauss=# CREATE INCREMENTAL MATERIALIZED VIEW mv AS SELECT * FROM t1;
CREATE MATERIALIZED VIEW
-- 插入数据
openGauss=# INSERT INTO t1 VALUES(3, 3);
INSERT 0 1
-- 增量刷新物化视图
openGauss=# REFRESH INCREMENTAL MATERIALIZED VIEW mv;
REFRESH MATERIALIZED VIEW
-- 查询物化视图结果
openGauss=# SELECT * FROM mv;
 c1 | c2 
----+----
  1 |  1
  2 |  2
  3 |  3
(3 rows)
-- 插入数据
openGauss=# INSERT INTO t1 VALUES(4, 4);
INSERT 0 1
-- 全量刷新物化视图
openGauss=# REFRESH MATERIALIZED VIEW mv;
REFRESH MATERIALIZED VIEW
-- 查询物化视图结果
openGauss=# select * from mv;
 c1 | c2 
----+----
  1 |  1
  2 |  2
  3 |  3
  4 |  4
(4 rows)
-- 删除物化视图
openGauss=# DROP MATERIALIZED VIEW mv;
DROP MATERIALIZED VIEW
```