---
title: "pg_statistic_ext_data"
id: catalog-pg-statistic-ext-data
pg_version: "20devel"
---

<a id="catalog-pg-statistic-ext-data"></a>

## 52.58. pg_statistic_ext_data

The catalog pg_statistic_ext_data holds data for extended planner statistics defined in [pg_statistic_ext](catalog-pg-statistic-ext.md). Each row in this catalog corresponds to a *statistics object* created with [`CREATE STATISTICS`](sql-createstatistics.md). 

Normally there is one entry, with `stxdinherit` = `false`, for each statistics object that has been analyzed. If the table has inheritance children or partitions, a second entry with `stxdinherit` = `true` is also created. This row represents the statistics object over the inheritance tree, i.e., statistics for the data you'd see with `SELECT * FROM table*`, whereas the `stxdinherit` = `false` row represents the results of `SELECT * FROM ONLY table`. 

Like [pg_statistic](catalog-pg-statistic.md), pg_statistic_ext_data should not be readable by the public, since the contents might be considered sensitive. (Example: most common combinations of values in columns might be quite interesting.) [pg_stats_ext](view-pg-stats-ext.md) is a publicly readable view on pg_statistic_ext_data (after joining with [pg_statistic_ext](catalog-pg-statistic-ext.md)) that only exposes information about tables the current user owns. 

**pg_statistic_ext_data Columns**

| Column Type | Description | 
| --- | --- |
| `stxoid` `oid` (references [pg_statistic_ext](catalog-pg-statistic-ext.md).`oid`) | Extended statistics object containing the definition for this data |
| `stxdinherit` `bool` | If true, the stats include values from child tables, not just the values in the specified relation |
| `stxdndistinct` `pg_ndistinct` | N-distinct counts, serialized as pg_ndistinct type |
| `stxddependencies` `pg_dependencies` | Functional dependency statistics, serialized as pg_dependencies type |
| `stxdmcv` `pg_mcv_list` | MCV (most-common values) list statistics, serialized as pg_mcv_list type |
| `stxdexpr` `pg_statistic[]` | Per-expression statistics, serialized as an array of pg_statistic type |