yunfan123 commented on code in PR #24104: URL: https://github.com/apache/flink/pull/24104#discussion_r1462659082
########## docs/content/docs/dev/table/sql/queries/joins.md: ########## @@ -326,6 +326,17 @@ FROM Orders AS o In the example above, the Orders table is enriched with data from the Customers table which resides in a MySQL database. The `FOR SYSTEM_TIME AS OF` clause with the subsequent processing time attribute ensures that each row of the `Orders` table is joined with those Customers rows that match the join predicate at the point in time when the `Orders` row is processed by the join operator. It also prevents that the join result is updated when a joined `Customer` row is updated in the future. The lookup join also requires a mandatory equality join predicate, in the example above `o.customer_id = c.id`. +### Partitioned Lookup Join +Some lookup source connectors use cache to reduce RPC call times. In order to raise cache hit ratio for those connectors, user could use a hint to enable partitioned lookup join which enforces input of lookup join to hash shuffle by look up keys. + +```sql +-- enable partitioned lookup join by partitioned hint Review Comment: Thanks for your comments, I will use `SHUFFLE_HASH ` hint. -- 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]
