Re: Delay in completion of aggregation inserts when run in a single commit - PG 9.1.2

Akash Kodibail wrote:
> Problem:
[...]
>
> - Aggregation process almost never completes which is a set of 15
insert queries. Entire
> process happens in a single commit (population of staging tables and
aggregation).
>
> - When I run these 15 queries individually, it happens in no time.
>
> Could you be kind enough to explain how differently queries run when
in a "single commit" as opposed
> to running each of them individually?

Apart from minor differences (current_timestamp, ...) the
main difference is that there is no COMMIT after each query.
COMMIT is expensive since it requires a write to hard disk.

Try to get the execution plans of the queries in both cases
and see if you can spot a difference.
The auto_explain contrib module might come handy for that.

Yours,
Laurenz Albe