DESCRIBE STATISTICS

Displays computed histogram statistics metadata for a table, including histogram methods, bin counts, and column coverage.

Category: statisticsDeltaForge extension

Syntax

DESCRIBE STATISTICS <table>

Description

## Overview Displays metadata about the histogram statistics and bloom filter indexes that have been computed for a table via ANALYZE TABLE. This is the primary diagnostic command for understanding what statistics are available to the query optimizer. ## Behavior - The command reads the HistogramStatisticsMetadata domain metadata from the Delta transaction log. - The result includes: column names covered by histograms, the histogram method used, number of bins, sample rate at the time of computation, top-k configuration, and whether bloom filters are configured. - If no statistics have been computed for the table, the result set is empty. - The command is read-only and does not modify the table or its metadata. - Statistics metadata reflects the most recent ANALYZE TABLE run. Historical statistics from prior versions are not shown (use DESCRIBE HISTORY to find the version at which statistics were computed). ## Result Columns The result set contains metadata about each analyzed column, including: - Column name - Data type - Histogram method - Number of bins - Row count sampled - Whether a bloom filter is configured ## Access Control | Privilege | Object | Notes | |-----------|--------|-------| | Read access | Target table | Required to inspect table metadata. | ## Compatibility DESCRIBE STATISTICS is a DeltaForge extension. Standard SQL defines no equivalent command for inspecting optimizer statistics.

Parameters

Name	Type	Description
`table`		Specifies the table name or path for which to display statistics. Supports fully qualified names (zone.schema.table).

Examples

-- View statistics for a table
DESCRIBE STATISTICS orders;

-- View statistics using a fully qualified name
DESCRIBE STATISTICS analytics.sales.transactions;

-- Check statistics after running ANALYZE TABLE
ANALYZE TABLE orders COMPUTE STATISTICS FOR COLUMNS (customer_id, amount);
DESCRIBE STATISTICS orders;

Pitfalls

The output reflects only the latest statistics. If the table has been significantly modified since the last ANALYZE TABLE run, the displayed statistics may not represent current data distribution.
An empty result does not mean the table has no statistics at all. Delta tables always maintain per-file min/max statistics in the transaction log; DESCRIBE STATISTICS only shows histogram-level statistics created by ANALYZE TABLE.