lirui-apache commented on a change in pull request #12609:
URL: https://github.com/apache/flink/pull/12609#discussion_r439183606
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File path: docs/dev/table/hive/hive_streaming.md
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@@ -163,4 +163,33 @@ SELECT * FROM hive_table /*+
OPTIONS('streaming-source.enable'='true', 'streamin
## Hive Table As Temporal Tables
-TODO
+Starting from Flink 1.11.0, you can use a Hive table as temporal table and
join streaming data with it. Please follow
+the [example]({{ site.baseurl
}}/dev/table/streaming/temporal_tables.html#temporal-table) to find out how to
join a
+temporal table. When performing the join, the Hive table will be cached in TM
memory and each record from the stream
+is looked up in the Hive table to decide whether a match is found. You don't
need any extra settings to use a Hive table
+as temporal table. But optionally, you can configure the TTL of the Hive table
cache with the following
+property. After the cache expires, the Hive table will be scanned again to
load the latest data.
+
+<table class="table table-bordered">
+ <thead>
+ <tr>
+ <th class="text-left" style="width: 20%">Key</th>
+ <th class="text-left" style="width: 15%">Default</th>
+ <th class="text-left" style="width: 10%">Type</th>
+ <th class="text-left" style="width: 55%">Description</th>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td><h5>lookup.join.cache.ttl</h5></td>
+ <td style="word-wrap: break-word;">60 min</td>
+ <td>Duration</td>
+ <td>The cache TTL (e.g. 10min) for the build table in lookup join. By
default the TTL is 60 minutes.</td>
+ </tr>
+ </tbody>
+</table>
+
+**Note**:
+1. You need to make sure the Hive table can fit into TM memory since the whole
table will be cached.
+2. You should set a relatively large value for `lookup.join.cache.ttl`. You'll
probably have performance issue if
+your Hive table needs to be updated and reloaded too frequently.
Review comment:
I have mentioned that the whole table will be cached. And the temporal
table can be either partitioned or non-partitioned. It seems to me that talking
about new/old partitions here might bring more confusions.
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