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https://issues.apache.org/jira/browse/FLINK-27434?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17529942#comment-17529942
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wuwenchi commented on FLINK-27434:
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[~fsk119] Thanks for your reply!
We want iceberg to support flink's watermarks and computed columns, so we need
to record the expressions of watermarks and computed columns into its table
properties, which can be understood as a separate storage. When flink reads the
table again, the expression that needs to read the table properties is passed
to flink.
But this table property can be modified by other engines (such as spark), so
the expression needs to be verified when reading the expression. This process
is not to get a ResolvedSchema from flink, but to structure a Schema, and then
return a table to flink through CatalogTable#of.
In order for this table to be correct, I need to verify the expressions of the
watermark and computed columns.
> How to convert 'Schema' to 'ResolvedSchema' within 'Catalog'?
> -------------------------------------------------------------
>
> Key: FLINK-27434
> URL: https://issues.apache.org/jira/browse/FLINK-27434
> Project: Flink
> Issue Type: Technical Debt
> Components: Table SQL / API
> Affects Versions: 1.14.4
> Reporter: wuwenchi
> Priority: Major
>
> I would like to support watermarks and computed columns in iceberg and put
> expressions for these properties into iceberg table properties. So when the
> user is modifying the corresponding expression, how can I verify the
> correctness of the expression?
> I want to do a build with 'Schema' and then convert to 'ResolvedSchema',
> but I can't get the 'schemaResolver' which is a primary member of
> CatalogManager.
> So, how do I get schemaResolver? Or is there an interface in flink that
> provides expression verification function for watermarks and computed columns?
>
>
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