PG-147: Store top query, instead of parent query.

docs/USER_GUIDE.md

@@ -352,41 +352,34 @@ postgres=# SELECT bucket, substr(query,0, 50) AS query, cmd_type FROM pg_stat_mo
 
 #### Function Execution Tracking 
 
-**`parentid`**: Outer layer caller's query id.
+**`top_queryid`**: Outer layer caller's query id.
 
 ```sql
-postgres=# select prosrc from pg_proc where proname = 'getnum';
+CREATE OR REPLACE FUNCTION add(int, int) RETURNS INTEGER AS
-             prosrc             
+$$
---------------------------------
+BEGIN
- select * from t1 where a >= $1
+	return (select $1 + $2);
-(1 row)
+END; $$ language plpgsql;
 
-postgresr=# select pg_stat_monitor_reset();
- pg_stat_monitor_reset 
------------------------
 
-(1 row)
+CREATE OR REPLACE function add2(int, int) RETURNS int as
+$$
+BEGIN
+	return add($1,$2);
+END;
+$$ language plpgsql;
 
-postgres=# select prosrc from pg_proc where proname = 'getnum';
+SELECT add2(1,2);
-             prosrc             
+ sub
---------------------------------
+-----
- select * from t1 where a >= $1
-(1 row)
-
-postgres=# select * from getnum(2);
- a 
----
- 2
    3
- 4
+(1 row)
-(3 rows)
 
-postgres=# select queryid,parentid,query,calls from pg_stat_monitor;
+postgres=# SELECT queryid, top_queryid, query, top_query FROM pg_stat_monitor;
-     queryid      |     parentid     |                     query                     | calls 
+     queryid      |   top_queryid    |                                                       query                                                        |     top_query
-------------------+------------------+-----------------------------------------------+-------
+------------------+------------------+--------------------------------------------------------------------------------------------------------------------+-------------------
- 3FEC80684AFE7FC7 | DD2A4843140299C2 | select * from t1 where a >= $1                |     1
+ 3408CA84B2353094 |                  | select add2($1,$2)                                                                                                 |
- 6ED05FFB78DD52FA |                  | select pg_stat_monitor_reset()                |     1
+ 2BAB410CC448CE8D | 3408CA84B2353094 | SELECT add($1,$2)                                                                                                  | select add2($1,$2)
- DD2A4843140299C2 |                  | select * from getnum($1)                      |     1
+ 762B99349F6C7F31 | 3408CA84B2353094 | SELECT (select $1 + $2)                                                                                            | select add2($1,$2)
- 42517D48FB98ACF7 |                  | select prosrc from pg_proc where proname = $1 |     1
+(3 rows)
-(4 rows)
 ```

pg_stat_monitor--1.0.sql

@@ -31,7 +31,7 @@ CREATE FUNCTION pg_stat_monitor(IN showtext boolean,
     OUT client_ip           int8,
 
     OUT queryid             text,
-    OUT parentid            text,
+    OUT top_queryid            text,
     OUT query               text,
 	OUT application_name	text,
 	OUT relations			text,
@@ -126,9 +126,9 @@ CREATE VIEW pg_stat_monitor AS SELECT
     datname,
 	'0.0.0.0'::inet + client_ip AS client_ip,
     queryid,
-    parentid,
+    top_queryid,
     query,
-	(SELECT query from pg_stat_monitor(true) s where s.queryid = p.parentid) AS parent_query,
+	(SELECT query from pg_stat_monitor(true) s where s.queryid = p.top_queryid) AS top_query,
 	application_name,
 	string_to_array(relations, ',') AS relations,
 	cmd_type,