[PGPRO-12159] Added three missing pageinspect functions for rum.

1) rum_internal_data_page_items() - it is intended for viewing information
   that is located on the internal pages of the posting tree (flags {data}).
2) rum_leaf_entry_page_items() - it is intended for viewing information
   that is located on the leaf pages of the entry tree (flags {leaf}).
3) rum_internal_entry_page_items() - it is intended for viewing information
   that is located on the internal pages of the entry tree (flags {}).

To extract information, all these functions need to pass the index name
and the page number.

Tags: rum

Author: arseny114

rum_init.sql

@@ -6,7 +6,6 @@ LANGUAGE C;
 /*
  * RUM access method
  */
-
 CREATE ACCESS METHOD rum TYPE INDEX HANDLER rumhandler;
 
 /*
@@ -1738,7 +1737,7 @@ CREATE FUNCTION rum_metapage_info(
     OUT n_entry_pages bigint,
     OUT n_data_pages bigint,
     OUT n_entries bigint,
-    OUT version bigint)
+    OUT version varchar)
 AS 'MODULE_PATHNAME', 'rum_metapage_info'
 LANGUAGE C STRICT PARALLEL SAFE;
 
@@ -1756,9 +1755,48 @@ LANGUAGE C STRICT PARALLEL SAFE;
 CREATE FUNCTION rum_leaf_data_page_items(
     IN rel_name text,
     IN blk_num int8,
+    OUT is_high_key bool,
     OUT tuple_id tid,
     OUT add_info_is_null bool,
-    OUT addInfo varchar)
+    OUT add_info varchar)
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'rum_leaf_data_page_items'
 LANGUAGE C STRICT PARALLEL SAFE;
+
+CREATE FUNCTION rum_internal_data_page_items(
+    IN rel_name text,
+    IN blk_num int8,
+    OUT is_high_key bool,
+    OUT block_number int8,
+    OUT tuple_id tid,
+    OUT add_info_is_null bool,
+    OUT add_info varchar)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'rum_internal_data_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+CREATE FUNCTION rum_leaf_entry_page_items(
+    IN rel_name text,
+    IN blk_num int8,
+    OUT key varchar,
+    OUT attrnum int8,
+    OUT category varchar,
+    OUT tuple_id tid,
+    OUT add_info_is_null bool,
+    OUT add_info varchar,
+    OUT is_postring_tree bool,
+    OUT postring_tree_root int8)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'rum_leaf_entry_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+CREATE FUNCTION rum_internal_entry_page_items(
+    IN rel_name text,
+    IN blk_num int8,
+    OUT key varchar,
+    OUT attrnum int8,
+    OUT category varchar,
+    OUT down_link int8)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'rum_internal_entry_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;