Lists every Delta table currently registered with the metastore together with its hydration state (`cached_through_version`, `log_head_version`, last hydration time).
SHOW METASTORE## Overview Returns a row per metastore-mirrored table with the operator-facing health signals: which version the metastore authoritatively serves, what the most recent log head observed was, and when the last hydration ran. Read-only; never modifies metastore state. ## When to use SHOW METASTORE is the primary operator surface for the metastore. Run it when you need to answer any of: - **"Is this table cached?"** quick presence check before deciding whether a query will benefit from the metastore path. - **"Is the metastore falling behind?"** compute `log_head_version - cached_through_version` per row. A non-zero, growing lag means `ALTER METASTORE ... REFRESH` is overdue (or the background refresher has stalled). - **"Which tables haven't been refreshed recently?"** the `last_hydrated_at` column tells you. Tables you expected to be tracked but haven't refreshed in hours are a signal that an automation broke. - **"What's the catalog footprint?"** total mirrored tables tells you roughly how much per-table partition state the metastore is carrying. - **Routine health-check / monitoring.** Plug SHOW METASTORE into a Grafana / cron probe that alerts when lag exceeds a threshold. - **Before-and-after for CREATE / ALTER / DROP METASTORE operations.** SHOW METASTORE confirms the operation landed as expected. SHOW METASTORE is **read-only and cheap**, it touches only `table_registry` and `cache_state`, which are small and indexed. It's safe to call frequently from monitoring without affecting query performance. ## Columns returned | Column | Description | |--------|-------------| | `table_qname` | Canonical 3-part name of the cached table. | | `partition_suffix` | Internal Postgres-identifier slug used for per-table partitions. | | `cached_through_version` | Highest Delta version fully ingested by the metastore. The planner answers queries AS OF this version. NULL means the registry row exists but no hydration has completed yet. | | `log_head_version` | Most recent log head observed during the last hydration probe. NULL means no probe has run since the mirror was created. | | `last_hydrated_at` | Timestamp of the last successful hydration pass. | | `registered_at` | When CREATE METASTORE was first run for this table. | | `last_seen_at` | Most recent time the registry row was touched (CREATE / ALTER REFRESH). | ## Access Control | Privilege | Object | Notes | |-----------|--------|-------| | (none) | Metastore | SHOW METASTORE is a metadata read; no per-table permission is enforced. Future versions may filter by the caller's READ permissions. |
-- Status board of every cached table.
SHOW METASTORE;