Materialize v0.38

v0.38.0

• Add cpu_percent_normalized to the mz_internal.mz_{source,sink,cluster_replica}_utilization system catalog views. This column provides an approximation of CPU utilization as a % of the total of compute workers.

• Add mz_internal.mz_cluster_replica_frontiers to the system catalog. This table describes the frontiers of each dataflow in the system.

• Private preview. Support the AS OF and UP TO clauses in SUBSCRIBE. These clauses allow specifying a timestamp at which SUBSCRIBE should begin returning results (AS OF), or cease running (UP TO).

  As is, all user-defined sources and tables have a retention window of one second, so AS OF is of limited use beyond subscribing to queries over specific system catalog objects (including mz_cluster_replicas, mz_sources, mz_sinks, mz_internal.mz_cluster_replica_metrics, and mz_internal.mz_cluster_replica_sizes).