[DBM] Add datadog.column_stats() function to Postgres setup docs

Add the column_stats() SECURITY DEFINER function to all 8 Postgres
DBM setup guides (selfhosted, RDS, Aurora, Azure, GCP Cloud SQL,
AlloyDB, Heroku, Supabase). This function enables the Agent to
collect column statistics from pg_stats for Database Monitoring.

Author: ethanperez

content/en/database_monitoring/setup_postgres/alloydb.md

@@ -107,6 +107,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/aurora.md

@@ -142,6 +142,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/azure.md

@@ -190,6 +190,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/gcsql.md

@@ -106,6 +106,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/heroku.md

@@ -73,6 +73,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ## Configuring the Postgres integration
 
 Next, configure the Datadog agent to enable the Postgres integration, using one of the following two options.

content/en/database_monitoring/setup_postgres/rds/_index.md

@@ -202,6 +202,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/selfhosted.md

@@ -165,6 +165,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 {{% dbm-secret %}}
 

content/en/database_monitoring/setup_postgres/supabase.md

@@ -114,6 +114,21 @@ RETURNS NULL ON NULL INPUT
 SECURITY DEFINER;
 ```
 
+Create the function **in every database** to enable the Agent to collect column statistics.
+
+```SQL
+CREATE OR REPLACE FUNCTION datadog.column_stats() RETURNS TABLE (
+    schemaname name, tablename name, attname name,
+    n_distinct real, avg_width integer, null_frac real
+) AS
+$$
+  SELECT schemaname, tablename, attname, n_distinct, avg_width, null_frac
+  FROM pg_stats;
+$$
+LANGUAGE sql
+SECURITY DEFINER;
+```
+
 ### Securely store your password
 
 {{% dbm-secret %}}