Re: [HACKERS] psql nested queries with 2000+ records

At 12:24 PM 3/20/98 -0500, Bruce Momjian wrote:

>Very strange. 15+ minutes? Wow, that is terrible, even longer than a
>sequential scan of the table. Try EXPLAIN and tell us what it says in
>the two cases.

This is within the 2717 record database.

explain select name from games where name in (select name from games where
name like 'A%');

NOTICE: QUERY PLAN:

Seq Scan on games (cost=207.95 size=446 width=12)
SubPlan
-> Seq Scan on games (cost=207.95 size=1 width=12)

NOTICE: QUERY PLAN:

Seq Scan on games (cost=207.95 size=446 width=12)
SubPlan
-> Seq Scan on games (cost=207.95 size=1 width=12)

EXPLAIN

This is within the 24 record database of the same type of data

explain select name from games where name in (select name from game
s where name like 'A%');
NOTICE: QUERY PLAN:

Seq Scan on games (cost=207.95 size=446 width=12)
SubPlan
-> Seq Scan on games (cost=207.95 size=1 width=12)

NOTICE: QUERY PLAN:

Seq Scan on games (cost=207.95 size=446 width=12)
SubPlan
-> Seq Scan on games (cost=207.95 size=1 width=12)

EXPLAIN

Obviously, I get the same information, any suggestions?

-Coronach(at)hill-b-073(dot)resnet(dot)purdue(dot)edu