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schemanamename (referencespg_namespace.nspname)

Name of schema containing table

tablenamename (referencespg_class.relname)

Name of table the statistics object is defined on

statistics_schemanamename (referencespg_namespace.nspname)

Name of schema containing extended statistics object

statistics_namename (referencespg_statistic_ext.stxname)

Name of extended statistics object

statistics_ownername (referencespg_authid.rolname)

Owner of the extended statistics object

exprtext

Expression included in the extended statistics object

inheritedbool (referencespg_statistic_ext_data.stxdinherit)

If true, the stats include values from child tables, not just the values in the specified relation

null_fracfloat4

Fraction of expression entries that are null

avg_widthint4

Average width in bytes of expression's entries

n_distinctfloat4

If greater than zero, the estimated number of distinct values in the expression. If less than zero, the negative of the number of distinct values divided by the number of rows. (The negated form is used whenANALYZE believes that the number of distinct values is likely to increase as the table grows; the positive form is used when the expression seems to have a fixed number of possible values.) For example, -1 indicates a unique expression in which the number of distinct values is the same as the number of rows.

most_common_valsanyarray

A list of the most common values in the expression. (Null if no values seem to be more common than any others.)

most_common_freqsfloat4[]

A list of the frequencies of the most common values, i.e., number of occurrences of each divided by total number of rows. (Null whenmost_common_vals is.)

histogram_boundsanyarray

A list of values that divide the expression's values into groups of approximately equal population. The values inmost_common_vals, if present, are omitted from this histogram calculation. (This expression is null if the expression data type does not have a< operator or if themost_common_vals list accounts for the entire population.)

correlationfloat4

Statistical correlation between physical row ordering and logical ordering of the expression values. This ranges from -1 to +1. When the value is near -1 or +1, an index scan on the expression will be estimated to be cheaper than when it is near zero, due to reduction of random access to the disk. (This expression is null if the expression's data type does not have a< operator.)

most_common_elemsanyarray

A list of non-null element values most often appearing within values of the expression. (Null for scalar types.)

most_common_elem_freqsfloat4[]

A list of the frequencies of the most common element values, i.e., the fraction of rows containing at least one instance of the given value. Two or three additional values follow the per-element frequencies; these are the minimum and maximum of the preceding per-element frequencies, and optionally the frequency of null elements. (Null whenmost_common_elems is.)

elem_count_histogramfloat4[]

A histogram of the counts of distinct non-null element values within the values of the expression, followed by the average number of distinct non-null elements. (Null for scalar types.)