LB-Yu commented on code in PR #24104: URL: https://github.com/apache/flink/pull/24104#discussion_r1463174712
########## docs/content.zh/docs/dev/table/sql/queries/joins.md: ########## @@ -324,6 +324,16 @@ FROM Orders AS o 在上面的示例中，Orders 表由保存在 MySQL 数据库中的 Customers 表数据来丰富。带有后续 process time 属性的 `FOR SYSTEM_TIME AS OF` 子句确保在联接运算符处理 `Orders` 行时，`Orders` 的每一行都与 join 条件匹配的 Customer 行连接。它还防止连接的 `Customer` 表在未来发生更新时变更连接结果。lookup join 还需要一个强制的相等连接条件，在上面的示例中是 `o.customer_id = c.id`。 +### Hash Shuffle Lookup Join +一些Lookup join source使用缓存来减少访问维表的次数。为了提高这些连接器的缓存命中率，用户可以使用一个SQL Hint来启用预分区能力，这会强制在Lookup Join之前，按Join key进行一次hash。 +```sql +-- 使用shuffle hash hint开启 partitioned lookup join Review Comment: Should the expressions in the document uniformly use SHFFLE_HASH? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
