Re: Partition insert trigger using C language

On Thu, Jan 10, 2013 at 4:54 PM, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com
> wrote:

> On 10.01.2013 20:45, Matheus de Oliveira wrote:
>
>> Inspired by Charles' thread and the work of Emmanuel [1], I have made some
>> experiments trying to create a trigger to make partitioning using C
>> language.
>>
>> The first attempt was not good, I tried to use SPI [2] to create a query
>> to
>> insert into the correct child table, but it took almost no improvement
>> compared with the PL/pgSQL code.
>>
>
> The right way to do this with SPI is to prepare each insert-statement on
> first invocation (SPI_prepare + SPI_keepplan), and reuse the plan after
> that (SPI_execute_with_args).
>
> If you construct and plan the query on every invocation, it's not
> surprising that it's no different from PL/pgSQL performance.
>
>
Yeah. I thought about that, but the problem was that I assumed the INSERTs
came with random date, so in the worst scenario I would have to keep the
plans of all of the child partitions. Am I wrong?

But thinking better, even with hundreds of partitions, it wouldn't use to
much memory/resource, would it?

In fact, I didn't give to much attention to SPI method, because the other
one is where we can have more fun, =P.

Anyway, I'll change the code (maybe now), and see if it gets closer to the
other method (that uses heap_insert), and will post back the results here.

Thanks,
--
Matheus de Oliveira
Analista de Banco de Dados
Dextra Sistemas - MPS.Br nível F!
www.dextra.com.br/postgres