Document why Iceberg table needs to be external in metastore

trinodb · Feb 24, 2022 · 4d2dc44 · 4d2dc44
1 parent c5f5a1f
commit 4d2dc44
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/...eberg/src/main/java/io/trino/plugin/iceberg/catalog/AbstractMetastoreTableOperations.java b/...eberg/src/main/java/io/trino/plugin/iceberg/catalog/AbstractMetastoreTableOperations.java
@@ -193,10 +193,12 @@ protected void commitNewTable(TableMetadata metadata)
                 .setDatabaseName(database)
                 .setTableName(tableName)
                 .setOwner(owner)
+                // Table needs to be EXTERNAL, otherwise table rename in HMS would rename table directory and break table contents.
                 .setTableType(TableType.EXTERNAL_TABLE.name())
                 .setDataColumns(toHiveColumns(metadata.schema().columns()))
                 .withStorage(storage -> storage.setLocation(metadata.location()))
                 .withStorage(storage -> storage.setStorageFormat(STORAGE_FORMAT))
+                // This is a must-have property for the EXTERNAL_TABLE table type
                 .setParameter("EXTERNAL", "TRUE")
                 .setParameter(TABLE_TYPE_PROP, ICEBERG_TABLE_TYPE_VALUE)
                 .setParameter(METADATA_LOCATION_PROP, newMetadataLocation);