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

At 09:54 AM 3/21/98 -0500, Bruce Momjian wrote:

>Try it without the LIKE, with just an equals.

amusements=> explain select name from games where name in (select name from
game
s where mfr = '');
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

--

amusements=> explain select name from games where name in (select name from
game
s2 where mfr = '');
NOTICE: QUERY PLAN:

Seq Scan on games (cost=207.95 size=446 width=12)
SubPlan
-> Seq Scan on games2 (cost=10.23 size=1 width=12)

EXPLAIN

The first query approved to be lengthy, but the last query was executed and
returned rows in just a few.

I then did an explain on a query that refered to the games table within the
sub query.

amusements=> explain select name from games where name in (select name from
game
s where mfr = '');
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

For the nature of the searches that the front end send to postgres (the
database is used with a web interface), it is nec. to use the like
expression. Where should I go from here?

Thanks once again,

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