Hi Flavio: I just implement a JDBCLookupFunction[1]. You can use it as table function[2]. Or use blink temporal table join[3] (Need blink planner support). I add a google guava cache in JDBCLookupFunction with configurable cacheMaxSize (avoid memory OOM) and cacheExpireMs(For the fresh of lookup table). Is that you want?
[1] https://github.com/JingsongLi/flink/blob/cc80999279b38627b37fa7550fb6610eee450d86/flink-connectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java [2] https://github.com/JingsongLi/flink/blob/cc80999279b38627b37fa7550fb6610eee450d86/flink-connectors/flink-jdbc/src/test/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunctionITCase.java#L143 [3] https://github.com/apache/flink/blob/master/flink-table/flink-table-planner-blink/src/test/scala/org/apache/flink/table/runtime/stream/sql/LookupJoinITCase.scala#L75 Best, JingsongLee ------------------------------------------------------------------ From:Flavio Pompermaier <pomperma...@okkam.it> Send Time:2019年6月28日(星期五) 21:04 To:user <user@flink.apache.org> Subject:LookupableTableSource question Hi to all, I have a use case where I'd like to enrich a stream using a rarely updated lookup table. Basically, I'd like to be able to set a refresh policy that is triggered either when a key was not found (a new key has probably been added in the mean time) or a configurable refresh-period has elapsed. Is there any suggested solution to this? The LookupableTableSource looks very similar to what I'd like to achieve but I can't find a real-world example using it and it lacks of such 2 requirements (key-values are not refreshed after a configurable timeout and a KeyNotFound callback cannot be handled). Any help is appreciated, Flavio
