Hi Liam, Thanks for starting this discussion!
To clarity: Does a view with a custom location work in Polaris if the location is a subpath inside allowedLocations? Thanks, Dmitri. On Thu, May 29, 2025 at 9:57 PM Liam Bao <liam.zw....@gmail.com> wrote: > Hi everyone, > > I’d like to bring up a discussion around the expected behavior of the > write.metadata.path config, which is used to set a custom metadata location > for tables and views. > > Currently, Polaris does *not allow* creating a view with > write.metadata.path > outside of the allowedLocations defined in the storageConfig. I’ve > documented this behavior in #1320 > <https://github.com/apache/polaris/pull/1320>, and I’d like to clarify > what > the intended behavior should be moving forward. > Summary of Current Behavior 1. *View Creation with Custom Metadata Path* > > A view *cannot be created* with a write.metadata.path outside of > allowedLocations, *unless*: > > - The parent namespace defines write.metadata.path, and > - The view’s write.metadata.path is a *subpath* of the namespace-defined > value. > > > > This logic is implemented here > < > https://github.com/apache/polaris/blob/989e99ae51f6cef0c093a86a4e51796f99a6894d/polaris-core/src/main/java/org/apache/polaris/core/storage/PolarisStorageConfigurationInfo.java#L184-L191 > >, > where the namespace config overrides storage settings. > > *Example:* > If the namespace sets write.metadata.path=file://baseLocation, then the > view can be created at file://baseLocation/customLocation. > 2. *Editing a View’s Metadata Path to a Sibling Location* > > Once the view is created, updating its write.metadata.path to a sibling > path (e.g., file://baseLocation/customLocation2) is *not allowed*. > > *Reason:* > The validation during update uses the *view’s own* write.metadata.path, not > the namespace’s config. > 3. *Editing to a Subpath Also Fails* > > Updating write.metadata.path to a *subpath* (e.g., from > file://baseLocation/customLocation to > file://baseLocation/customLocation/child) fails. > > *Reason:* > This is rejected because after creation, the view’s write.metadata.path is > stored in internalProperties rather than properties, so the previous config > override no longer applies. > Questions to Discuss: > > - What is the *intended behavior* of write.metadata.path? > - The override logic > < > https://github.com/apache/polaris/blob/989e99ae51f6cef0c093a86a4e51796f99a6894d/polaris-core/src/main/java/org/apache/polaris/core/storage/PolarisStorageConfigurationInfo.java#L184-L191 > > > doesn't appear to be covered by existing tests. I'm wondering about the > original purpose behind it. > > > > Looking forward to your feedback! > Best, > Liam >
