Re: Avoiding a seq scan on a table.

On Jan 14, 2008 12:14 PM, LWATCDR <lwatcdr(at)gmail(dot)com> wrote:

> Really? From what I have done in writing my own code I have found
> hashing to be faster than a btree but then when I wrote my own hashing
> it was a specific type of key.
> Anyway I put in the tree indexes and I am still getting a seq scan.
>
> Aggregate (cost=12.12..12.13 rows=1 width=0)
> -> Result (cost=0.00..12.12 rows=1 width=0)
> One-Time Filter: NULL::boolean
> -> Seq Scan on issuetracking (cost=0.00..12.12 rows=1 width=0)
> Filter: (((issue_target)::text = 'david'::text) OR
> ((manager)::text = 'david'::text))

The Postgres planner will choose what it thinks is the fastest plan. In
this case, your table has only 1 row (?), so sequential scan will be
fastest. You will want to load data into your table before doing
benchmarking.

Sean