Re: Avoiding a seq scan on a table.
| От | Sean Davis |
|---|---|
| Тема | Re: Avoiding a seq scan on a table. |
| Дата | |
| Msg-id | 264855a00801140925x3208fa30x98ad59547a8679cc@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Avoiding a seq scan on a table. (LWATCDR <lwatcdr@gmail.com>) |
| Список | pgsql-novice |
On Jan 14, 2008 12:14 PM, LWATCDR <lwatcdr@gmail.com> wrote:
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
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
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