I don’t think this implementation is correct for Polaris.
It appears to satisfy the inherited Iceberg createTableInUniqueLocation test, but it does not trace all of Polaris’s create-location paths.

The main issue is that defaultWarehouseLocation(...) and buildPrefixedLocation(...) are shared by more than "direct table create without an explicit location":

• Direct table create calls buildTable(...).withLocation(request.location()).create(). When request.location() is null, the Polaris table builder can route through transformTableLikeLocation(...), and depending on prefix config may use buildPrefixedLocation(...) or defaultWarehouseLocation(...).
• Staged table create without a location uses buildTable(...).createTransaction().table().location() in IcebergCatalogHandler.stageTableCreateHelper(...). That does not call withLocation(null), so it bypasses the same transform path used by direct create. This means direct create and staged create can derive different locations under DEFAULT_LOCATION_OBJECT_STORAGE_PREFIX_ENABLED.
• Views also use the same catalog default-location machinery. createView(...) eventually calls .withLocation(request.location()), and the Polaris view builder also calls transformTableLikeLocation(...). If buildPrefixedLocation(...) or defaultWarehouseLocation(...) blindly uses LocationUtil.tableLocation(...), then views can inherit unique-table-location and get a viewName-uuid suffix, which is not what Iceberg’s table-specific unique-table-location property should mean.

I think the fix needs a table-specific helper for deriving default table create locations, and both direct create and staged create should use that helper when the request has no explicit location. View default locations should stay view-name-based, and namespace/register/load/drop/rename paths should not be affected.

The fix also need targeted tests for those changes.

I don’t think this implementation is correct for Polaris. It appears to satisfy the inherited Iceberg createTableInUniqueLocation test, but it does not trace all of Polaris’s create-location paths.

The main issue is that defaultWarehouseLocation(...) and buildPrefixedLocation(...) are shared by more than "direct table create without an explicit location":

• Direct table create calls buildTable(...).withLocation(request.location()).create(). When request.location() is null, the Polaris table builder can route through transformTableLikeLocation(...), and depending on prefix config may use buildPrefixedLocation(...) or defaultWarehouseLocation(...).
• Staged table create without a location uses buildTable(...).createTransaction().table().location() in IcebergCatalogHandler.stageTableCreateHelper(...). That does not call withLocation(null), so it bypasses the same transform path used by direct create. This means direct create and staged create can derive different locations under DEFAULT_LOCATION_OBJECT_STORAGE_PREFIX_ENABLED.
• Views also use the same catalog default-location machinery. createView(...) eventually calls .withLocation(request.location()), and the Polaris view builder also calls transformTableLikeLocation(...). If buildPrefixedLocation(...) or defaultWarehouseLocation(...) blindly uses LocationUtil.tableLocation(...), then views can inherit unique-table-location and get a viewName-uuid suffix, which is not what Iceberg’s table-specific unique-table-location property should mean.

I think the fix needs a table-specific helper for deriving default table create locations, and both direct create and staged create should use that helper when the request has no explicit location. View default locations should stay view-name-based, and namespace/register/load/drop/rename paths should not be affected.

The fix also need targeted tests for those changes.

@snazy Thanks for the detailed review, it helped highlight the Polaris-specific create-location paths that weren't covered by the Iceberg compatibility test.

I've pushed an update that addresses the staged create and view-location concerns, and added targeted tests for both scenarios. I also updated the location derivation logic so direct and staged table creates follow the same path when unique-table-location is enabled.

Please take another look when you have a chance.