PG-310: Bucket is “Done” vs still being current/last. (#321)

A new column is added to mention that bucket is active or done. there is    
some timing based adjustment was required with that too.   

Co-authored-by: Hamid Akhtar <hamid.akhtar@percona.com>

pg_stat_monitor--2.0.sql

@@ -126,7 +126,7 @@ CREATE FUNCTION pg_stat_monitor_internal(
 	OUT elevel              int,
     OUT sqlcode             TEXT,
     OUT message             text,
-    OUT bucket_start_time   timestamp,
+    OUT bucket_start_time   timestamptz,
 
 	OUT calls         		int8,  -- 16
 
@@ -165,7 +165,8 @@ CREATE FUNCTION pg_stat_monitor_internal(
     OUT wal_fpi 			int8,
     OUT wal_bytes 			numeric,
     OUT comments 			TEXT,
-    OUT toplevel            BOOLEAN
+    OUT toplevel            BOOLEAN,
+	OUT bucket_done			BOOLEAN
 )
 RETURNS SETOF record
 AS 'MODULE_PATHNAME', 'pg_stat_monitor_2_0'
@@ -219,7 +220,8 @@ CREATE VIEW pg_stat_monitor AS SELECT
 	cpu_sys_time,
     wal_records,
     wal_fpi,
-    wal_bytes
+    wal_bytes,
+	bucket_done
 FROM pg_stat_monitor_internal(TRUE) p, pg_database d  WHERE dbid = oid
 ORDER BY bucket_start_time;
 RETURN 0;
@@ -276,6 +278,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     wal_records,
     wal_fpi,
     wal_bytes,
+	bucket_done,
     -- PostgreSQL-13 Specific Coulumns
 	plans_calls,
 	total_plan_time,
@@ -338,6 +341,7 @@ CREATE VIEW pg_stat_monitor AS SELECT
     wal_records,
     wal_fpi,
     wal_bytes,
+	bucket_done,
 
     plans_calls,
 	total_plan_time,