从补丁 198 开始，Amazon Redshift 将不再支持创建新的 Python UDF。现有的 Python UDF 将继续正常运行至 2026 年 6 月 30 日。有关更多信息，请参阅[博客文章](https://www.amazonaws.cn/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/)。

# ALTER MATERIALIZED VIEW 的 DISTSTYLE 和 SORTKEY 示例
<a name="r_ALTER_MATERIALIZED_VIEW-DISTSTYLE-SORTKEY-examples"></a>

本主题中的示例向您展示了如何使用 ALTER MATERIAD VIEW 对 DISTYLE 和 SORTKEY 进行更改。

以下示例查询显示了如何使用示例基表更改 DISTSTYLE KEY DISTKEY 列：

```
CREATE TABLE base_inventory(
  inv_date_sk int4 NOT NULL,
  inv_item_sk int4 NOT NULL,
  inv_warehouse_sk int4 NOT NULL,
  inv_quantity_on_hand int4
);

INSERT INTO base_inventory VALUES(1,1,1,1);

CREATE materialized VIEW inventory diststyle even AS SELECT * FROM base_inventory;
SELECT "table", diststyle FROM svv_table_info WHERE "table" = 'inventory';

ALTER materialized VIEW inventory ALTER diststyle KEY distkey inv_warehouse_sk;
SELECT "table", diststyle FROM svv_table_info WHERE "table" = 'inventory';

ALTER materialized VIEW inventory ALTER distkey inv_item_sk;
SELECT "table", diststyle FROM svv_table_info WHERE "table" = 'inventory';

DROP TABLE base_inventory CASCADE;
```

将实体化视图更改为 DISTSTYLE ALL：

```
CREATE TABLE base_inventory(
  inv_date_sk int4 NOT NULL,
  inv_item_sk int4 NOT NULL,
  inv_warehouse_sk int4 NOT NULL,
  inv_quantity_on_hand int4
);

INSERT INTO base_inventory VALUES(1,1,1,1);

CREATE materialized VIEW inventory diststyle even AS SELECT * FROM base_inventory;
SELECT "table", diststyle FROM svv_table_info WHERE "table" = 'inventory';

ALTER MATERIALIZED VIEW inventory ALTER diststyle ALL;
SELECT "table", diststyle FROM svv_table_info WHERE "table" = 'inventory';

DROP TABLE base_inventory CASCADE;
```

以下命令显示了使用示例基表的 ALTER MATERIALIZED VIEW SORTKEY 示例：

```
CREATE TABLE base_inventory (c0 int, c1 int);

INSERT INTO base_inventory VALUES(1,1);

CREATE materialized VIEW inventory interleaved sortkey(c0, c1) AS SELECT * FROM base_inventory;
SELECT "table", sortkey1 FROM svv_table_info WHERE "table" = 'inventory';

ALTER materialized VIEW inventory ALTER sortkey(c0, c1);
SELECT "table", diststyle, sortkey_num FROM svv_table_info WHERE "table" = 'inventory';

ALTER materialized VIEW inventory ALTER sortkey NONE;
SELECT "table", diststyle, sortkey_num FROM svv_table_info WHERE "table" = 'inventory';

ALTER materialized VIEW inventory ALTER sortkey(c0);
SELECT "table", diststyle, sortkey_num FROM svv_table_info WHERE "table" = 'inventory';

DROP TABLE base_inventory CASCADE;
```