Hi, Today, let me discuss some thing about PG Optimizer while taking a better execution plan. Seq Scan (vs) Index Scan ---------------------------------- Both scans having its own pros and cons. Sometimes, seq scan will give you the better execution time and sometimes Index scan. Let's find out.. Step 1:- postgres=# CREATE TABLE TEST(T INT PRIMARY KEY); NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "test_pkey" for table "test" CREATE TABLE postgres=# INSERT INTO TEST VALUES(GENERATE_SERIES(1,100)); INSERT 0 100 Step 2:- Check the no.of pages occupied by the table "test" from pg_class. postgres=# ANALYZE TEST; ANALYZE postgres=# SELECT RELNAME,RELPAGES FROM PG_CLASS WHERE relname like 'test'; relname | relpages ---------+---------- test | 1 Step 3:- Find the below execution plans. postgres=# EXPLAIN ANALYZE SELECT * FROM TEST WHERE T=10; ...