Fields idx_scan and idx_tup_fetch are not changed by an index scan.
=# create table class1 (id integer); CREATE TABLE =# -- Insert 0..9999 into class1 =# create index
class1_id_indexon class1 (id); CREATE INDEX =# vacuum analyze; VACUUM =# \x Expanded display is on. =#
select* from pg_stat_all_tables where relname = 'class1'; -[ RECORD 1 ]-+------- relid | 17166 schemaname
| public relname | class1 seq_scan | 2 seq_tup_read | 13000 idx_scan | 0 idx_tup_fetch | 0
n_tup_ins | 10000 n_tup_upd | 0 n_tup_del | 0
=# \x Expanded display is off. =# explain select * from class1 where id = 1234; QUERY PLAN
------------------------------------------------------------------------------ Index
Scanusing class1_id_index on class1 (cost=0.00..3.01 rows=2 width=4) Index Cond: (id = 1234) (2 rows)
=# \x Expanded display is on. =# select * from pg_stat_all_tables where relname = 'class1'; -[ RECORD 1
]-+------- relid | 17166 schemaname | public relname | class1 seq_scan | 2 seq_tup_read
|13000 idx_scan | 0 idx_tup_fetch | 0 n_tup_ins | 10000 n_tup_upd | 0 n_tup_del | 0
=#
Kenji Sugita