Thanks Jark and the un-ordered mode is useful in some cases. Jark Wu <imj...@gmail.com> 于2020年2月28日周五 下午7:18写道：
> Hi, > > The ordering in streaming SQL is very important, because the accumulate > and retract messages are emitted in order. > If messages are out of order, the result will be wrong. Think of you are > applying an un-ordered changelog, the result will be non-deterministic. > That's why we only support "ordered" mode for async lookup join. > > The support for "un-ordered" mode is on the roadmap, but that will be more > complex, because the planner should check it doesn't affect > the order of acc/retract messages (e.g. it is just an append-only stream). > > I created https://issues.apache.org/jira/browse/FLINK-16332 to track this > feature. > > Best, > Jark > > > On Fri, 28 Feb 2020 at 18:33, 郑泽辉 <closee...@gmail.com> wrote: > >> >> >> ---------- Forwarded message --------- >> 发件人： StevenZheng <closee...@gmail.com> >> Date: 2020年2月28日周五 下午6:30 >> Subject: Re: How to set unorderedWait/orderedWait properties in Table API >> when using Async I/O >> To: Danny Chan <yuzhao....@gmail.com> >> >> >> Thanks Danny and I do run my lookupfunction in a single thread like this >> commit:https://github.com/apache/flink/pull/10356, and my customized >> source is a jdbc table source. >> >> But actually I still want to know, how to define the return order of >> async results and if it is possible to do that. >> >> Danny Chan <yuzhao....@gmail.com> 于2020年2月27日周四 下午9:38写道： >> >>> The lookup event is indeed triggered by the AsyncWaitOperator, the blink >>> AsyncLookupJoinRunner is nested into that. >>> But we only generates the AsyncWaitOperator when the >>> LookupableTableSource#isAsyncEnabled returns true, now only >>> InMemoryLookupableTableSource supports that. >>> >>> One thing need to note is that you should execute the logic in >>> LookupableTableSource with a separate thread if your source is custom. >>> >>> So >>> >>> 1. What dimension table source do you use ? >>> 2. If you customized you source, did you run it in a separate thread >>> ? >>> >>> >>> Best, >>> Danny Chan >>> 在 2020年2月26日 +0800 PM9:14，郑泽辉 <closee...@gmail.com>，写道： >>> >>> Hi all, >>> I'm using Blink Planner(flink v1.9) and I create a AsyncJdbcTableSource >>> class implements LookupableTableSource, but when I override the >>> getAsyncLookupFunction(), I found the results of async method(by Vertx) is >>> in order. >>> >>> But I don't need the stream order is preserved and just want the result >>> records emitted out of order to improve processing speed. In DataStream API >>> I can easily set the result order guarantee( >>> https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/operators/asyncio.html#order-of-results), >>> and my question is, >>> >>> how to set this in Table API or SQL API with Blink Planner? >>> >>> Thanks. Regards >>> >>>
