Lists all row-level indexes on a table along with their status, version binding, algorithm, leaf count, and on-disk size.
DESCRIBE INDEXES ON TABLE <table>## Overview DESCRIBE INDEXES returns one row per index defined on a table. Use it to verify an index's state, check whether it is up to date with the parent, and inspect its on-disk footprint. ## Output schema | Column | Type | Description | |--------|------|-------------| | name | STRING | Index name as supplied at CREATE INDEX | | id | STRING | Internal index id | | columns | STRING | Comma-separated list of indexed columns in prefix order | | algorithm | STRING | `pgm` or `btree` | | auto_update | BOOLEAN | Whether parent writes maintain this index | | parent_version | BIGINT | Parent table version recorded in the registry | | child_version | BIGINT | Latest version of the child index Delta table | | status | STRING | Index lifecycle status (active, tombstoned, ...) | | leaf_count | BIGINT | Number of leaf records in the child index | | size_bytes | BIGINT | Total on-disk size of the child index Delta table | ## Behavior - Indexes whose status is tombstoned (dropped but not yet vacuumed) appear with `leaf_count = 0` and `size_bytes = 0`; the underlying child files may still exist on disk until the child path is vacuumed. - A discrepancy between the registry's `parent_version` and the parent's current version indicates the index is stale and the planner will fall back for rows changed after that version. - The query loads each child snapshot to compute exact leaf and size statistics, so DESCRIBE INDEXES is more expensive than a pure metadata read. ## Access Control No specific privilege is required beyond table-level access. ## Compatibility DeltaForge extension.
| Name | Type | Description |
|---|---|---|
table | Specifies the parent Delta table whose indexes to list. |
-- List all indexes on a table
DESCRIBE INDEXES ON TABLE orders;-- Use the result programmatically
DESCRIBE INDEXES ON TABLE orders;
-- Returns one row per index with columns:
-- name, id, columns, algorithm, auto_update, parent_version, child_version, status, leaf_count, size_bytes