query_stat_total improvements:

1) display warnings when DB is close to xidWrapLimit by 200M transactions
2) remove '\r' symbol from queries for better display at email clients

fix incorrect numbering of queries when there is no 'other' query, fix IO percentage at total time when there is very little / no activity on database since last pg_stat_statements reset.

sql/global_reports/query_stat_total.sql

@@ -1,5 +1,6 @@
 with pg_stat_statements_normalized as (
     select *,
+    translate(
     regexp_replace(
     regexp_replace(
     regexp_replace(
@@ -7,13 +8,14 @@ with pg_stat_statements_normalized as (
     E'\\?(::[a-zA-Z_]+)?( *, *\\?(::[a-zA-Z_]+)?)+', '?', 'g'),
     E'\\$[0-9]+(::[a-zA-Z_]+)?( *, *\\$[0-9]+(::[a-zA-Z_]+)?)*', '$N', 'g'),
     E'--.*$', '', 'ng'),
-    E'/\\*.*?\\*/', '', 'g')
+    E'/\\*.*?\\*/', '', 'g'),
+    E'\r', '')
     as query_normalized
     --if current database is postgres then generate report for all databases otherwise generate for current database only
     from pg_stat_statements where dbid in (SELECT oid from pg_database where current_database() = 'postgres' or datname=current_database())
 ),
 totals as (
-    select sum(total_time) AS total_time, greatest(sum(blk_read_time+blk_write_time), 1) as io_time,
+    select sum(total_time) AS total_time, sum(blk_read_time+blk_write_time) as io_time,
     sum(total_time-blk_read_time-blk_write_time) as cpu_time, sum(calls) AS ncalls,
     sum(rows) as total_rows FROM pg_stat_statements
     WHERE dbid in (SELECT oid from pg_database where current_database() = 'postgres' or datname=current_database())
@@ -24,10 +26,12 @@ _pg_stat_statements as (
     (select rolname from pg_roles where oid = p.userid) as username,
     --select shortest query, replace \n\n-- strings to avoid email clients format text as footer
     substring(
+    translate(
     replace(
     (array_agg(query order by length(query)))[1],
     E'-- \n',
     E'--\n'),
+    E'\r', ''),
     1, 8192) as query,
     sum(total_time) as total_time,
     sum(blk_read_time) as blk_read_time, sum(blk_write_time) as blk_write_time,
@@ -46,7 +50,7 @@ totals_readable as (
 statements as (
     select
     (100*total_time/(select total_time from totals)) AS time_percent,
-    (100*(blk_read_time+blk_write_time)/(select io_time from totals)) AS io_time_percent,
+    (100*(blk_read_time+blk_write_time)/(select greatest(io_time, 1) from totals)) AS io_time_percent,
     (100*(total_time-blk_read_time-blk_write_time)/(select cpu_time from totals)) AS cpu_time_percent,
     to_char(interval '1 millisecond' * total_time, 'HH24:MI:SS') AS total_time,
     (total_time::numeric/calls)::numeric(20,2) AS avg_time,
@@ -60,11 +64,11 @@ statements as (
     username,
     query
     from _pg_stat_statements
-    where ((total_time-blk_read_time-blk_write_time)/(select cpu_time from totals)>=0.01 or (blk_read_time+blk_write_time)/(select io_time from totals)>=0.01 or calls/(select ncalls from totals)>=0.02 or rows/(select total_rows from totals)>=0.02)
+    where ((total_time-blk_read_time-blk_write_time)/(select cpu_time from totals)>=0.01 or (blk_read_time+blk_write_time)/(select greatest(io_time, 1) from totals)>=0.01 or calls/(select ncalls from totals)>=0.02 or rows/(select total_rows from totals)>=0.02)
 union all
     select
     (100*sum(total_time)::numeric/(select total_time from totals)) AS time_percent,
-    (100*sum(blk_read_time+blk_write_time)::numeric/(select io_time from totals)) AS io_time_percent,
+    (100*sum(blk_read_time+blk_write_time)::numeric/(select greatest(io_time, 1) from totals)) AS io_time_percent,
     (100*sum(total_time-blk_read_time-blk_write_time)::numeric/(select cpu_time from totals)) AS cpu_time_percent,
     to_char(interval '1 millisecond' * sum(total_time), 'HH24:MI:SS') AS total_time,
     (sum(total_time)::numeric/sum(calls))::numeric(20,2) AS avg_time,
@@ -78,7 +82,7 @@ union all
     'all' as username,
     'other' as query
     from _pg_stat_statements
-    where not ((total_time-blk_read_time-blk_write_time)/(select cpu_time from totals)>=0.01 or (blk_read_time+blk_write_time)/(select io_time from totals)>=0.01 or calls/(select ncalls from totals)>=0.02 or rows/(select total_rows from totals)>=0.02)
+    where not ((total_time-blk_read_time-blk_write_time)/(select cpu_time from totals)>=0.01 or (blk_read_time+blk_write_time)/(select greatest(io_time, 1) from totals)>=0.01 or calls/(select ncalls from totals)>=0.02 or rows/(select total_rows from totals)>=0.02)
 ),
 statements_readable as (
     select row_number() over (order by s.time_percent desc) as pos,
@@ -88,15 +92,17 @@ statements_readable as (
     to_char(avg_io_time*100/(coalesce(nullif(avg_time, 0), 1)), 'FM990.0') || '%' AS avg_io_time_percent,
     total_time, avg_time, avg_cpu_time, avg_io_time, calls, calls_percent, rows, row_percent,
     database, username, query
-    from statements s
+    from statements s where calls is not null
 )
 
 select E'total time:\t' || total_time || ' (IO: ' || io_time_percent || E'%)\n' ||
 E'total queries:\t' || total_queries || ' (unique: ' || unique_queries || E')\n' ||
-'report for ' || (select case when current_database() = 'postgres' then 'all databases' else current_database() || ' database' end) || E', version 0.9.4' ||
+'report for ' || (select case when current_database() = 'postgres' then 'all databases' else current_database() || ' database' end) || E', version 0.9.5' ||
 ' @ PostgreSQL ' || (select setting from pg_settings where name='server_version') || E'\ntracking ' || (select setting from pg_settings where name='pg_stat_statements.track') || ' ' ||
 (select setting from pg_settings where name='pg_stat_statements.max') || ' queries, utilities ' || (select setting from pg_settings where name='pg_stat_statements.track_utility') ||
-', logging ' || (select (case when setting = '0' then 'all' when setting = '-1' then 'none' when setting::int > 1000 then (setting::numeric/1000)::numeric(20, 1) || 's+' else setting || 'ms+' end) from pg_settings where name='log_min_duration_statement') || E' queries\n\n'
+', logging ' || (select (case when setting = '0' then 'all' when setting = '-1' then 'none' when setting::int > 1000 then (setting::numeric/1000)::numeric(20, 1) || 's+' else setting || 'ms+' end) from pg_settings where name='log_min_duration_statement') || E' queries\n' ||
+(select coalesce(string_agg('WARNING: database ' || datname || ' must be vacuumed within ' || to_char(2147483647 - age(datfrozenxid), 'FM999,999,999,990') || ' transactions', E'\n' order by age(datfrozenxid) desc) || E'\n', '')
+ from pg_database where (2147483647 - age(datfrozenxid)) < 200000000) || E'\n'
 from totals_readable
 union all
 (select E'=============================================================================================================\n' ||