日本熟妇hd丰满老熟妇,中文字幕一区二区三区在线不卡 ,亚洲成片在线观看,免费女同在线一区二区

AI 助理
備案控制臺
文檔
輸入文檔關鍵字查找
首頁 實時計算 Flink版 操作指南 運維管理 作業(yè)狀態(tài)管理 Flink狀態(tài)兼容性 SQL修改及兼容性 變更Query

Top-N

更新時間：
產品詳情
我的收藏

本文為您介紹Top-N變更的可兼容性和不可兼容性詳情。

可兼容的變更

  • 修改partition key的順序，屬于完全兼容變更。

    --原始
select a, b, c from (
  select *,
   row_number() over (partition by a, b order by c) as rk
   from MyTable)
where rk < 3;

-- 修改partition key順序，屬于完全兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by b, a order by c) as rk
   from MyTable)
where rk < 3;

  • 是否輸出rank number的值，不影響兼容性，屬于完全兼容。

    -- 原始SQL。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 輸出rank number字段：rk，屬于完全兼容。
select a, b, c, rk from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

不兼容的變更

  • 如果rank是UpdateFastRank算法，且上游的Upsert Key發(fā)生了變化，屬于不兼容變更。

  • 新增、刪除、修改partition by key或者partition by key涉及字段的計算邏輯發(fā)生變化，屬于不兼容變更。

    -- 原始SQL。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 新增partition by字段：d，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a, d order by c) as rk
   from MyTable)
where rk < 3;

-- 刪除partition by字段：a，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (order by c) as rk
   from MyTable)
where rk < 3;

-- 修改partition by字段：a -> a + 1，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from (select a + 1 as a, b, c from MyTable))
where rk < 3;

  • 修改order by相關屬性（排序字段和方向），屬于不兼容變更。

    -- 原始SQL。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 修改order key：c -> b，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by b) as rk
   from MyTable)
where rk < 3;

-- 修改order key：c -> substring(c, 1, 5)，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from (select a, b, substring(c, 1, 5) as c from MyTable))
where rk < 3;

-- 修改order：asc -> desc，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c desc) as rk
   from MyTable)
where rk < 3;

  • 修改rank range的值（Top-N中N的值），屬于不兼容變更。

    -- 原始SQL。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 修改rank range：3 -> 5，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 5;

  • 修改了輸入字段，屬于不兼容變更。

    -- 原始SQL。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 新增輸入字段d，屬于不兼容變更。
select a, b, c, d from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 刪除輸入字段：b，屬于不兼容變更。
select a, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from MyTable)
where rk < 3;

-- 修改輸入字段：b -> b + 1，屬于不兼容變更。
select a, b, c from (
  select *,
   row_number() over (partition by a order by c) as rk
   from (select a, b + 1 as b, c from MyTable))
where rk < 3;