Add more columns to pg_stats, pg_stats_ext, and pg_stats_ext_exprs.

This commit adds table OID and attribute number columns to
pg_stats, and it adds table OID and statistics object OID columns
to pg_stats_ext and pg_stats_ext_exprs.  A proposed follow-up
commit would use pg_stats.tableid to simplify a query in pg_dump.
The others have no immediate purpose but may be useful later.

Bumps catversion.

Author: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Sami Imseih <samimseih@gmail.com>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/CADkLM%3DcoCVy92QkVUUTLdo5eO2bMDtwMrzRn_8miAhX%2BuPaqXg%40mail.gmail.com

doc/src/sgml/system-views.sgml

@@ -4414,6 +4414,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>tableid</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of table
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>attname</structfield> <type>name</type>
@@ -4424,6 +4434,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>attnum</structfield> <type>int2</type>
+       (references <link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link>.<structfield>attnum</structfield>)
+      </para>
+      <para>
+       Number of column described by this row
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>inherited</structfield> <type>bool</type>
@@ -4666,6 +4686,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>tableid</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of table
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>statistics_schemaname</structfield> <type>name</type>
@@ -4686,6 +4716,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>statistics_id</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-statistic-ext"><structname>pg_statistic_ext</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of extended statistics object
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>statistics_owner</structfield> <type>name</type>
@@ -4877,6 +4917,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>tableid</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-class"><structname>pg_class</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of table the statistics object is defined on
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>statistics_schemaname</structfield> <type>name</type>
@@ -4897,6 +4947,16 @@ SELECT * FROM pg_locks pl LEFT JOIN pg_prepared_xacts ppx
       </para></entry>
      </row>
 
+     <row>
+      <entry role="catalog_table_entry"><para role="column_definition">
+       <structfield>statistics_id</structfield> <type>oid</type>
+       (references <link linkend="catalog-pg-statistic-ext"><structname>pg_statistic_ext</structname></link>.<structfield>oid</structfield>)
+      </para>
+      <para>
+       OID of extended statistics object
+      </para></entry>
+     </row>
+
      <row>
       <entry role="catalog_table_entry"><para role="column_definition">
        <structfield>statistics_owner</structfield> <type>name</type>

src/backend/catalog/system_views.sql

@@ -191,7 +191,9 @@ CREATE VIEW pg_stats WITH (security_barrier) AS
     SELECT
         nspname AS schemaname,
         relname AS tablename,
+        attrelid AS tableid,
         attname AS attname,
+        attnum,
         stainherit AS inherited,
         stanullfrac AS null_frac,
         stawidth AS avg_width,
@@ -278,8 +280,10 @@ REVOKE ALL ON pg_statistic FROM public;
 CREATE VIEW pg_stats_ext WITH (security_barrier) AS
     SELECT cn.nspname AS schemaname,
            c.relname AS tablename,
+           s.stxrelid AS tableid,
            sn.nspname AS statistics_schemaname,
            s.stxname AS statistics_name,
+           s.oid AS statistics_id,
            pg_get_userbyid(s.stxowner) AS statistics_owner,
            ( SELECT array_agg(a.attname ORDER BY a.attnum)
              FROM unnest(s.stxkeys) k
@@ -312,8 +316,10 @@ CREATE VIEW pg_stats_ext WITH (security_barrier) AS
 CREATE VIEW pg_stats_ext_exprs WITH (security_barrier) AS
     SELECT cn.nspname AS schemaname,
            c.relname AS tablename,
+           s.stxrelid AS tableid,
            sn.nspname AS statistics_schemaname,
            s.stxname AS statistics_name,
+           s.oid AS statistics_id,
            pg_get_userbyid(s.stxowner) AS statistics_owner,
            stat.expr,
            sd.stxdinherit AS inherited,

src/include/catalog/catversion.h

@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202603162
+#define CATALOG_VERSION_NO	202603171
 
 #endif

src/test/regress/expected/rules.out

@@ -2546,7 +2546,9 @@ pg_statio_user_tables| SELECT relid,
   WHERE ((schemaname <> ALL (ARRAY['pg_catalog'::name, 'information_schema'::name])) AND (schemaname !~ '^pg_toast'::text));
 pg_stats| SELECT n.nspname AS schemaname,
     c.relname AS tablename,
+    a.attrelid AS tableid,
     a.attname,
+    a.attnum,
     s.stainherit AS inherited,
     s.stanullfrac AS null_frac,
     s.stawidth AS avg_width,
@@ -2638,8 +2640,10 @@ pg_stats| SELECT n.nspname AS schemaname,
   WHERE ((NOT a.attisdropped) AND has_column_privilege(c.oid, a.attnum, 'select'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
 pg_stats_ext| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
+    s.stxrelid AS tableid,
     sn.nspname AS statistics_schemaname,
     s.stxname AS statistics_name,
+    s.oid AS statistics_id,
     pg_get_userbyid(s.stxowner) AS statistics_owner,
     ( SELECT array_agg(a.attname ORDER BY a.attnum) AS array_agg
            FROM (unnest(s.stxkeys) k(k)
@@ -2666,8 +2670,10 @@ pg_stats_ext| SELECT cn.nspname AS schemaname,
   WHERE (pg_has_role(c.relowner, 'USAGE'::text) AND ((c.relrowsecurity = false) OR (NOT row_security_active(c.oid))));
 pg_stats_ext_exprs| SELECT cn.nspname AS schemaname,
     c.relname AS tablename,
+    s.stxrelid AS tableid,
     sn.nspname AS statistics_schemaname,
     s.stxname AS statistics_name,
+    s.oid AS statistics_id,
     pg_get_userbyid(s.stxowner) AS statistics_owner,
     stat.expr,
     sd.stxdinherit AS inherited,

src/test/regress/expected/stats_import.out

@@ -78,7 +78,7 @@ SELECT COUNT(*) FROM pg_attribute
     attnum > 0;
  count 
 -------
-    15
+    17
 (1 row)
 
 -- Create a view that is used purely for the type based on pg_stats_ext.
@@ -119,7 +119,7 @@ SELECT COUNT(*) FROM pg_attribute
     attnum > 0;
  count 
 -------
-    20
+    22
 (1 row)
 
 -- Create a view that is used purely for the type based on pg_stats_ext_exprs.