Re: BUG #14750: Seq Scan instead of Index Scan works without limitation

Seq Scan is fine except its ignore PRIMARY KEY and UNIQUE CONSTRAINT: in case result is found it should be immediatly returned to avoid scan rest of data:

# explain analyze select accountid from accounts where accountname = 'accountId50';
Seq Scan on accounts (cost=0.00..2.50 rows=1 width=12) (actual time=0.018..0.029 rows=1 loops=1)
Filter: ((accountname)::text = 'accountId50'::text)
Rows Removed by Filter: 119
Planning time: 0.075 ms
Execution time: 0.048 ms

In product no 'LIMIT 1' specified because first found result expected; in case of huge amout simple queries difference is valuable:

# explain analyze select accountid from accounts where accountname = 'accountId50' limit 1;
Limit (cost=0.00..2.50 rows=1 width=12) (actual time=0.016..0.016 rows=1 loops=1)
-> Seq Scan on accounts (cost=0.00..2.50 rows=1 width=12) (actual time=0.014..0.014 rows=1 loops=1)
Filter: ((accountname)::text = 'accountId50'::text)
Rows Removed by Filter: 50
Planning time: 0.084 ms
Execution time: 0.035 ms