pnowojski commented on a change in pull request #6897: [FLINK-9737]
[FLINK-8880] [sql-client] Support defining temporal tables in environment files
URL: https://github.com/apache/flink/pull/6897#discussion_r227267053
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File path: docs/dev/table/sqlClient.md
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@@ -503,7 +504,49 @@ Views created within a CLI session can also be removed
again using the `DROP VIE
DROP VIEW MyNewView;
{% endhighlight %}
-<span class="label label-danger">Attention</span> The definition of views is
limited to the mentioned syntax above. Defining a schema for views or escape
whitespaces in table names will be supported in future versions.
+<span class="label label-danger">Attention</span> The definition of views in
the CLI is limited to the mentioned syntax above. Defining a schema for views
or escaping whitespaces in table names will be supported in future versions.
+
+{% top %}
+
+Temporal Tables
+---------------
+
+A [temporal table](./streaming/temporal_tables.html) allows for a
(parameterized) view on a changing history table that returns the content of a
table at a specific point in time. This is especially useful for joining a
table with the content of another table at a particular timestamp. More
information can be found in the [temporal table
joins](./streaming/joins.html#join-with-a-temporal-table) page.
+
+The following example shows how to define a temporal table
`SourceTemporalTable`:
+
+{% highlight yaml %}
+tables:
+
+ # Define the table source (or view) that contains updates to a temporal table
+ - name: HistorySource
+ type: source-table
+ update-mode: append
+ connector: # ...
+ format: # ...
+ schema:
+ - name: integerField
+ type: INT
+ - name: stringField
+ type: VARCHAR
+ - name: rowtimeField
+ type: TIMESTAMP
+ rowtime:
+ timestamps:
+ type: from-field
+ from: rowtimeField
+ watermarks:
+ type: from-source
+
+ # Define a temporal table over the changing history table with time
attribute and primary key
+ - name: SourceTemporalTable
+ type: temporal-table
+ changing-table: HistorySource
Review comment:
`changing-table` is not very good name and it's inconsistent with already
used nomenclature, that even you are using here :) (`History***`). Maybe change
it to `underlying-table`, `underlying-history-table`, `history-table` or
something like that? If you think that there is some better name, please also
make the effort to rename existing `underlyingHistoryTable` occurrences in the
source code.
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