> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/internals/catalogs/catalog-pg-statistic-ext-data.md).

# 52.53. pg\_statistic\_ext\_data \#

The catalog `pg_statistic_ext_data` holds data for extended planner statistics defined in [`pg_statistic_ext`](/internals/catalogs/catalog-pg-statistic-ext.md). Each row in this catalog corresponds to a *statistics object* created with [`CREATE STATISTICS`](/reference/sql-commands/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`](/internals/catalogs/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`](/internals/views/view-pg-stats-ext.md) is a publicly readable view on `pg_statistic_ext_data` (after joining with [`pg_statistic_ext`](/internals/catalogs/catalog-pg-statistic-ext.md)) that only exposes information about tables the current user owns.

**Table 52.53. `pg_statistic_ext_data` Columns**

| <p>Column Type</p><p>Description</p>                                                                                                                                                                                         |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| <p><code>stxoid</code> <code>oid</code> (references <a href="/pages/PBajbiDNekbIsqryC08c"><code>pg\_statistic\_ext</code></a>.<code>oid</code>)</p><p>Extended statistics object containing the definition for this data</p> |
| <p><code>stxdinherit</code> <code>bool</code></p><p>If true, the stats include values from child tables, not just the values in the specified relation</p>                                                                   |
| <p><code>stxdndistinct</code> <code>pg\_ndistinct</code></p><p>N-distinct counts, serialized as <code>pg\_ndistinct</code> type</p>                                                                                          |
| <p><code>stxddependencies</code> <code>pg\_dependencies</code></p><p>Functional dependency statistics, serialized as <code>pg\_dependencies</code> type</p>                                                                  |
| <p><code>stxdmcv</code> <code>pg\_mcv\_list</code></p><p>MCV (most-common values) list statistics, serialized as <code>pg\_mcv\_list</code> type</p>                                                                         |
| <p><code>stxdexpr</code> <code>pg\_statistic\[]</code></p><p>Per-expression statistics, serialized as an array of <code>pg\_statistic</code> type</p>                                                                        |

<br>

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/catalog-pg-statistic-ext-data.html)（英文原文，待翻譯）


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