From 5e45211a64149b3c659b90ff2de6fa982a5a93ed Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 4 May 2024 14:17:33 +0200 Subject: Adding upstream version 15.5. Signed-off-by: Daniel Baumann --- doc/src/sgml/html/functions-statistics.html | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 doc/src/sgml/html/functions-statistics.html (limited to 'doc/src/sgml/html/functions-statistics.html') diff --git a/doc/src/sgml/html/functions-statistics.html b/doc/src/sgml/html/functions-statistics.html new file mode 100644 index 0000000..210bb3f --- /dev/null +++ b/doc/src/sgml/html/functions-statistics.html @@ -0,0 +1,24 @@ + +9.30. Statistics Information Functions
9.30. Statistics Information Functions
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9.30. Statistics Information Functions

9.30.1. Inspecting MCV Lists

+ PostgreSQL provides a function to inspect complex + statistics defined using the CREATE STATISTICS command. +

9.30.1. Inspecting MCV Lists

+pg_mcv_list_items ( pg_mcv_list ) → setof record
+

+ pg_mcv_list_items returns a set of records describing + all items stored in a multi-column MCV list. It + returns the following columns: + +

NameTypeDescription
indexintegerindex of the item in the MCV list
valuestext[]values stored in the MCV item
nullsboolean[]flags identifying NULL values
frequencydouble precisionfrequency of this MCV item
base_frequencydouble precisionbase frequency of this MCV item

+

+ The pg_mcv_list_items function can be used like this: + +

+SELECT m.* FROM pg_statistic_ext join pg_statistic_ext_data on (oid = stxoid),
+                pg_mcv_list_items(stxdmcv) m WHERE stxname = 'stts';
+

+ + Values of the pg_mcv_list type can be obtained only from the + pg_statistic_ext_data.stxdmcv + column. +

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9.29. Event Trigger Functions Home Chapter 10. Type Conversion
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