PMM-14368 Fixes

Author: artemgavrilov

collector/pg_stat_bgwriter.go

@@ -220,29 +220,29 @@ const statCheckpointerQueryPrePG18 = `
 		SELECT
 			num_timed,
 			num_requested,
-			num_done,
+			NULL::bigint as num_done,
 			restartpoints_timed,
 			restartpoints_req,
 			restartpoints_done,
 			write_time,
 			sync_time,
 			buffers_written,
-			slru_written,
+			NULL::bigint as slru_written,
 			stats_reset
 		FROM pg_stat_checkpointer;`
 
 const statCheckpointerQueryPostPG18 = `
 		SELECT
 			num_timed,
 			num_requested,
-			NULL::bigint as num_done,
+			num_done,
 			restartpoints_timed,
 			restartpoints_req,
 			restartpoints_done,
 			write_time,
 			sync_time,
 			buffers_written,
-			NULL::bigint as slru_written,
+			slru_written,
 			stats_reset
 		FROM pg_stat_checkpointer;`
 

collector/pg_stat_io.go

@@ -140,15 +140,15 @@ var (
 			object,
 			context,
 			reads,
-			NULL:bigint as read_bytes,
+			NULL::bigint as read_bytes,
 			read_time,
 			writes,
-			NULL:bigint as write_bytes,
+			NULL::bigint as write_bytes,
 			write_time,
 			writebacks,
 			writeback_time,
 			extends,
-			NULL:numeric as extend_bytes,
+			NULL::numeric as extend_bytes,
 			extend_time,
 			hits,
 			evictions,

collector/pg_stat_user_tables.go

@@ -207,10 +207,10 @@ var (
 			analyze_count,
 			autoanalyze_count,
 			pg_total_relation_size(relid) as total_size,
-			NULL::double as total_vacuum_time,
-			NULL::double as total_autovacuum_time,
-			NULL::double as total_analyze_time,
-			NULL::double as total_autoanalyze_time
+			NULL::double precision as total_vacuum_time,
+			NULL::double precision as total_autovacuum_time,
+			NULL::double precision as total_analyze_time,
+			NULL::double precision as total_autoanalyze_time
 		FROM pg_stat_user_tables;`
 
 	statUserTablesQueryPostPG18 = `