52.51. pg\_statistic\_ext\_data

|   52.51. `pg_statistic_ext_data`    |                   |                           |                  |                                     |
|:-----------------------------------:|-------------------|---------------------------|------------------|-------------------------------------|
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## 52.51. `pg_statistic_ext_data`

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

 Like [`pg_statistic`](catalog-pg-statistic.html), `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.html) is a publicly readable view on `pg_statistic_ext_data` (after joining with [`pg_statistic_ext`](catalog-pg-statistic-ext.html)) that only exposes information about those tables and columns that are readable by the current user.

**Table 52.51. `pg_statistic_ext_data` Columns**

|                                                                 Column Type<br/><br/> Description                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|`stxoid` `oid` (references [`pg_statistic_ext`](catalog-pg-statistic-ext.html).`oid`)<br/><br/> Extended statistics object containing the definition for this data|
|                                  `stxdndistinct` `pg_ndistinct`<br/><br/> N-distinct counts, serialized as `pg_ndistinct` type                                   |
|                      `stxddependencies` `pg_dependencies`<br/><br/> Functional dependency statistics, serialized as `pg_dependencies` type                       |
|                           `stxdmcv` `pg_mcv_list`<br/><br/> MCV (most-common values) list statistics, serialized as `pg_mcv_list` type                           |
|                          `stxdexpr` `pg_statistic[]`<br/><br/> Per-expression statistics, serialized as an array of `pg_statistic` type                          |

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