[I] [Bug] Hive write of a multiset column fails with ClassCastException [paimon]

["thswlsqls (via GitHub)" <gi...@apache.org>]

thswlsqls opened a new issue, #9078:
URL: https://github.com/apache/paimon/issues/9078

   **Search before asking**
   - [x] I searched in the [issues](https://github.com/apache/paimon/issues) and found nothing similar.
   
   **Paimon version**
   master @ a5e87ebf6 (2.1-SNAPSHOT)
   
   **Compute Engine**
   Hive
   
   **Minimal reproduce step**
   Create a Paimon table with a `MULTISET<STRING>` column, then insert one row from Hive:
   
   ```sql
   INSERT INTO t SELECT 1, map('apple', 2);
   ```
   
   `PaimonSerDe.initialize()` succeeds — the object inspector is `struct<id:int,tags:map<string,int>>`, because #8949 added `case MULTISET:` to `PaimonObjectInspectorFactory`. The first `serialize()` call then fails:
   
   ```
   java.lang.ClassCastException: StandardMapObjectInspector cannot be cast to PrimitiveObjectInspector
     at org.apache.paimon.hive.HiveDeserializer$DeserializerVisitor.lambda$primitive$0(HiveDeserializer.java:117)
   ```
   
   `SchemaVisitor.visit()` (SchemaVisitor.java line 56-96) branches on `ROW`, `ARRAY` and `MAP` only, so `MULTISET` falls through to `default: return visitor.primitive(type, partner)`.
   
   **What doesn't meet your expectations?**
   Expected: the row is written, as reading the same column already works.
   Actual: reads work but every write of a multiset column throws.
   
   **Anything else?**
   Fix: visit `MULTISET` as `MapType(elementType, IntType)` — the mapping `PaimonObjectInspectorFactory` already uses on the read side (#8949).
   
   **Are you willing to submit a PR?**
   - [x] I'm willing to submit a PR!
   


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Re: [I] [Bug] Hive write of a multiset column fails with ClassCastException [paimon]

["JingsongLi (via GitHub)" <gi...@apache.org>]

JingsongLi closed issue #9078: [Bug] Hive write of a multiset column fails with ClassCastException
URL: https://github.com/apache/paimon/issues/9078


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