Trimming unused indexes
SELECT
pt.tablename AS TableName
,t.indexname AS IndexName
,pc.reltuples AS TotalRows
,pg_size_pretty(pg_relation_size(quote_ident(pt.tablename)::text)) AS TableSize
,pg_size_pretty(pg_relation_size(quote_ident(t.indexrelname)::text)) AS IndexSize
,t.idx_scan AS TotalNumberOfScan
,t.idx_tup_read AS TotalTupleRead
,t.idx_tup_fetch AS TotalTupleFetched
FROM pg_tables AS pt
LEFT OUTER JOIN pg_class AS pc
ON pt.tablename=pc.relname
LEFT OUTER JOIN
(
SELECT
pc.relname AS TableName
,pc2.relname AS IndexName
,psai.idx_scan
,psai.idx_tup_read
,psai.idx_tup_fetch
,psai.indexrelname
FROM pg_index AS pi
JOIN pg_class AS pc
ON pc.oid = pi.indrelid
JOIN pg_class AS pc2
ON pc2.oid = pi.indexrelid
JOIN pg_stat_all_indexes AS psai
ON pi.indexrelid = psai.indexrelid
)AS T
ON pt.tablename = T.TableName
WHERE pt.schemaname='public'
ORDER BY TotalNumberOfScan ASC;
You (may) need pg_stat_statements extension enabled for these stats to exist. (?)
I see a lot of indexes not being used. Would like to see more data from more instances.
Maintaining indexes on objects.actor_type
, objects.likes
, objects.tags
, activities.to
, activities.likes
, activities.in_reply_to
, activities.hosts
, activities.cc
, and activities.actor
but never actually using them seems quite expensive or we need to fix some queries...
Edited by feld