Hi. Just FYI, I have seen some catalogs are still use deprecated TableSchema in flink hive, Iceberg, etc connector. But it's in Flink plan to drop the deprecated table schema [1]. In long term, seems use new schema api is a better choice.
If it's for the case of Catalog's createTable method, from the code base [1], the passed CatalogBaseTable looks like should be a instance of ResolvedCatalogBaseTable with which you can get the resolve schema. From the commit history[3], since Flink 1.13, the pased CatalogBaseTable is intance of ResolvedCatalogBaseTable. I think maybe you can cast it ResolvedCatalogBaseTable and get the resolved schema. But please remeber, the cast will fail when the Flink version is lower than 1.13 since only from Flink 1.13, the passed CatalogBaseTable is intance of ResolvedCatalogBaseTable. [1] https://issues.apache.org/jira/browse/FLINK-29072 [2] https://github.com/apache/flink/blob/75a92efd7b35501698e5de253e5231d680830c16/flink-table/flink-table-api-java/src/main/java/org/apache/flink/table/catalog/CatalogManager.java#L654 [3] [ https://issues.apache.org/jira/browse/FLINK-21396 | https://issues.apache.org/jira/browse/FLINK-21396 ] Best regards, Yuxia 发件人: "Krzysztof Chmielewski" <krzysiek.chmielew...@gmail.com> 收件人: "User" <user@flink.apache.org> 发送时间: 星期六, 2023年 1 月 21日 上午 2:27:25 主题: Custom catalog implementation - getting table schema for computed columns Hi, I'm implementing a custom Catalog where for "create table" I need to get tables schema, both column names and types from DDL. Now the Catalog's createTable method has "CatalogBaseTable table" argument. The CatalogBaseTable has a deprecated "getSchema" and suggest to use getUnresolvedSchema instead. I was able to resolve schema types for physical columns, but I'm struggling with computed columns [1]. To be more precise I'm struggling to get//resolve the type of this field. I see that all implementations that would be needed to resolve inderlying expression of UnresolvedComputedColumn are marked as @Internal. On the other hand the deprecated "getSchema" has a proper type for this ComputedColumn. I'm wondering now, what should I do. Should I use the deprecated API that has what I need already or should I use suggested API and somehow try to resolve the type using @Internal classes which also does not seems safe. I would appreciate for any hint here. [1] [ https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/dev/table/sql/create/#:~:text=BIGINT%2C%20%60name%60%20STRING)-,Computed%20Columns,-Computed%20columns%20are | https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/dev/table/sql/create/#:~:text=BIGINT%2C%20%60name%60%20STRING)-,Computed%20Columns,-Computed%20columns%20are ]
