Statistics node: Extended Statistics support, completed (#9748, #2018)

docs/en_US/managing_database_objects.rst

@@ -39,6 +39,7 @@ node, and select *Create Cast...*
    publication_dialog
    schema_dialog
    sequence_dialog
+   statistics_dialog
    subscription_dialog
    synonym_dialog
    trigger_function_dialog

docs/en_US/statistics_dialog.rst

@@ -0,0 +1,88 @@
+.. _statistics_dialog:
+
+**************************
+`Statistics Dialog`:index:
+**************************
+
+Use the *Statistics* dialog to define extended statistics on one or more columns
+(or expressions) of a table. Extended statistics let PostgreSQL collect
+correlation data across columns that can significantly improve query-plan
+estimates for queries that filter or group by multiple columns.
+
+PostgreSQL introduced ``CREATE STATISTICS`` in PostgreSQL 10, and added
+expression statistics in PostgreSQL 14. This dialog is available for
+PostgreSQL 14 and later, which covers all currently supported PostgreSQL
+versions.
+
+The *Statistics* dialog organizes options across the *General* and *Definition*
+tabs. The *SQL* tab displays the SQL command generated by your selections.
+
+.. image:: images/statistics_general.png
+    :alt: Statistics dialog general tab
+    :align: center
+
+Use the fields in the *General* tab to describe the statistics object:
+
+* Use the *Name* field to enter a descriptive name. On PostgreSQL 16 and later
+  the name is optional, and the server will generate one from the table and the
+  columns or expressions if you leave it blank.
+* Use the *Owner* field to select the role that will own the statistics object.
+* Use the *Schema* field to select the schema in which the statistics object
+  will reside.
+* Use the *Table* field to select the table on which the statistics will be
+  collected. The list is filtered to tables in the selected schema.
+* Use the *Columns* field to select two or more columns. Hold *Ctrl* (or *Cmd*
+  on macOS) to select multiple columns. At least two columns are required when
+  collecting column based statistics, although a single column is enough when
+  it is combined with an expression.
+* Use the *Statistics types* field to choose which kinds of extended statistics
+  to collect:
+
+  * *N-distinct*, which estimates the number of distinct value combinations
+    across the selected columns or expressions.
+  * *Dependencies*, which detects functional dependencies between columns,
+    improving estimates for queries with correlated ``WHERE`` clauses.
+  * *MCV (Most Common Values)*, which records the most common combinations of
+    values.
+
+* Use the *Comment* field to store an optional note about the statistics object.
+
+Click the *Definition* tab to continue.
+
+.. image:: images/statistics_definition.png
+    :alt: Statistics dialog definition tab
+    :align: center
+
+* Use the *Expressions* field to enter one or more SQL expressions separated by
+  commas (for example ``lower(col1), (col1 + col2)``). Each expression must be
+  enclosed in parentheses unless it is a function call, and the list is passed
+  to the server exactly as you enter it, so an expression may itself contain
+  commas. Expressions may be given instead of columns, or alongside them when
+  you want statistics over a mixture of the two.
+
+When you open the dialog on an existing statistics object, the *Properties*
+view also reports the statistics target and, for roles with access, the values
+that ``ANALYZE`` has collected. Those values are held in
+``pg_catalog.pg_statistic_ext_data``, which is not publicly readable, so the
+*Computed Statistics* group is hidden when the current role lacks access.
+
+Click the *SQL* tab to continue.
+
+
+Your entries in the *Statistics* dialog generate a SQL command (see an example
+below). Use the *SQL* tab for review; revisit or switch tabs to make any changes.
+
+Example
+*******
+
+The following is an example of the SQL command generated by user selections in
+the *Statistics* dialog:
+
+.. image:: images/statistics_sql.png
+    :alt: Statistics dialog SQL tab
+    :align: center
+
+* Click the *Info* button (i) to access online help.
+* Click the *Save* button to save work.
+* Click the *Close* button to exit without saving work.
+* Click the *Reset* button to restore configuration parameters.

web/pgadmin/browser/server_groups/servers/databases/schemas/__init__.py

@@ -157,6 +157,9 @@ def register(self, app, options):
         from .sequences import blueprint as module
         self.submodules.append(module)
 
+        from .statistics import blueprint as module
+        self.submodules.append(module)
+
         from .synonyms import blueprint as module
         self.submodules.append(module)