added av query

sql/AutoVacuum/lagged_av_tables.sql

@@ -0,0 +1,22 @@
+-- This query gets those tables surpassing the threshold 
+-- * threshold = vac_base_thresh + vac_scale_factor * reltuples
+-- See https://github.com/postgres/postgres/blob/master/src/backend/postmaster/autovacuum.c#L3004
+-- FIXME! This query does not take into account that there could be custom AV options
+WITH base AS (
+			SELECT  schemaname||'.'|| relname as fullrelname,
+					current_setting('autovacuum_vacuum_threshold')::real + 
+					(current_setting('autovacuum_vacuum_scale_factor')::real*
+					n_live_tup) as threshold,
+					n_dead_tup as deadtuples
+			FROM pg_stat_user_tables
+		)
+SELECT     
+	fullrelname,
+	pg_size_pretty(pg_total_relation_size(fullrelname::regclass)) AS relationSize,
+	round(threshold) as threshold,
+	deadtuples
+FROM base
+WHERE 
+    deadtuples > threshold
+ORDER BY deadtuples DESC
+;