Your query time should be the sum of running the following two individual
queries:
1. SELECT MAX("Records"."timestamp") FROM "History" where "rowId" like ?
2. select "Records"."Operation", "Records"."status", "Records"."timestamp"
from "History" where "Records"."timestamp"=?
Without secondary indexing on column "timestamp", the first query will be
full-scan with aggregation and the second will be a full-scan with a filter
on the "timestamp" column.
Generally the higher parallel level (which depends on how many nodes you
have in your cluster and how many regions you have for the target table)
the better performance you get.
In this case, you could also have an secondary index on "timestamp" column
to avoid a full-table scan for the second query.
Thanks,
Maryann
On Tue, Nov 25, 2014 at 1:26 AM, Ahmed Hussien <aahussi...@gmail.com> wrote:
> Good Day to you guys,
>
> I have a db that contains about 33 million records per table (4 tables).
> when i execute the following queries it takes to much time to retrieve
> about 5 miniutes per query.
>
> 1- select "Records"."Operation", "Records"."status", "Records"."timestamp"
> from "History" where "Records"."timestamp"=(SELECT
> MAX("Records"."timestamp") FROM "History" where "rowId" like ?)
>
> can you help me adjust the performance?
> ---
> Ahmed
>
>
--
Thanks,
Maryann
