---
title: "Materialize v0.49"
date: 2023-04-05
released: true
patch: 6
---

## v0.49.0

#### SQL

* Change the type of the following system catalog replica ID columns from integer to string:

    * [`mz_catalog.mz_cluster_replicas.id`](/sql/system-catalog/mz_catalog/#mz_cluster_replicas)
    * [`mz_internal.mz_cluster_replica_statuses.replica_id`](/sql/system-catalog/mz_internal/#mz_cluster_replica_statuses)
    * `mz_internal.mz_cluster_replica_heartbeats.replica_id`
    * [`mz_internal.mz_cluster_replica_metrics.replica_id`](/sql/system-catalog/mz_internal/#mz_cluster_replica_metrics)
    * `mz_internal.mz_cluster_replica_frontiers.replica_id`

    This is part of the work to introduce system replicas, which Materialize
    will use for verification and testing purposes and which will not affect
    user billing or system limits {{% gh 11579 %}}. Note that, since
    `mz_catalog` is part of Materialize’s stable interface, the change to
    `mz_catalog.mz_cluster_replicas.id` is a **breaking change**.
    If this change causes you friction, please [let us know](https://materialize.com/s/chat).

* Add the [`ALTER OWNER`](/sql/alter-owner/) command, which updates the owner
  of an object. This is part of the work to enable **Role-based access
  control** (RBAC){{% gh 11579 %}}.

* Add permission checks based on object ownership. To `DROP` or `ALTER` an
  object, the executing role must now be an owner of that object or a
  superuser. This is part of the work to enable **Role-based access control**
  (RBAC){{% gh 11579 %}}.

* Apply `PRIMARY KEY`, `UNIQUE`, and `NOT NULL` constraints to tables ingested
  from PostgreSQL sources.

* Rename [replica introspection views](https://materialize.com/docs/sql/system-catalog/mz_introspection)
  for consistency, and use the `_per_worker` name suffix for per-worker introspection views.

* Automatically restart failed SSH tunnels to improve the reliability of
  SSH-tunneled Kafka sources.

#### Bug fixes and other improvements

- Fix a correctness bug in Top K processing for monotonic, append-only sources.

- Fix a bug that prevented superusers from altering an object owner if they weren't a member of the new owner's role.

- Fix a bug that would cause PostgreSQL sources to error when columns are added to upstream tables. Note that dropping columns from upstream tables that Materialize ingests still results in error.