52.53. pg_statistic_ext_data
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## 52.53. pg_statistic_ext_data #

The catalog pg_statistic_ext_data holds data for extended planner statistics defined in pg_statistic_ext. Each row in this catalog corresponds to a statistics object created with CREATE STATISTICS.

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, 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 is a publicly readable view on pg_statistic_ext_data (after joining with pg_statistic_ext) that only exposes information about tables the current user owns.

Table 52.53. pg_statistic_ext_data Columns

Column Type Description
`stxoid` oid (references pg_statistic_ext.`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

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