xuefuz commented on a change in pull request #8458: [FLINK-12452][table][hive]
alterTable() should ensure existing base table and the new one are of the same
type
URL: https://github.com/apache/flink/pull/8458#discussion_r284477579
##########
File path:
flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/table/catalog/hive/HiveCatalogBase.java
##########
@@ -318,13 +320,44 @@ public void alterTable(ObjectPath tablePath,
CatalogBaseTable newCatalogTable, b
throw new
TableNotExistException(catalogName, tablePath);
}
} else {
- // TODO: [FLINK-12452] alterTable() in all
catalogs should ensure existing base table and the new one are of the same type
+ Table oldTable = getHiveTable(tablePath);
+ TableType oldTableType =
TableType.valueOf(oldTable.getTableType());
+
+ // Flink cannot alter existing Hive tables in
types that Flink cannot create for now,
+ // including EXTERNAL_TABLE, INDEX_TABLE and
MATERIALZED_VIEW.
+ // Note that though Flink cannot create them,
it's able to read most parts of their metadata,
+ // like schema and properties, thru existing
mechanism, but not their unique metadata.
+ // Also note that add capability of creating
EXTERNAL_TABLE should be fairly easy to do, e.g. with a table property
+ // "table_type=external", we just haven't done
it yet.
+ // INDEX_TABLE and MATERIALZED_VIEW need more
research.
+
+ if (oldTableType == TableType.EXTERNAL_TABLE
+ || oldTableType ==
TableType.INDEX_TABLE
+ || oldTableType ==
TableType.MATERIALIZED_VIEW) {
+ throw new CatalogException(
+ String.format("The existing
Hive table is of type '%s', and HiveCatalogBase cannot handle it",
oldTableType.name()));
+ } else if (oldTableType ==
TableType.VIRTUAL_VIEW) {
+ if (!(newCatalogTable instanceof
CatalogView)) {
+ throw new CatalogException(
+ String.format("The
existing table is a view, but the new catalog base table is not."));
+ }
+ // Else, do nothing
+ } else if ((oldTableType ==
TableType.MANAGED_TABLE)) {
+ if (!(newCatalogTable instanceof
CatalogTable)) {
+ throw new CatalogException(
+ String.format("The
existing table is a table, but the new catalog base table is not."));
Review comment:
Nit: maybe start the message with "Table type doesn't match. ...."
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