Message-ID: <50EFE74B.9040007@vmware.com>
Date: Fri, 11 Jan 2013 12:19:55 +0200
From: Heikki Linnakangas <hlinnakangas@vmware.com>
Organization: VMware
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To: Matheus de Oliveira <matioli.matheus@gmail.com>
CC: pgsql-performance <pgsql-performance@postgresql.org>,
	Charles Gomes <charlesrg@outlook.com>
Subject: Re: Partition insert trigger using C language
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On 10.01.2013 21:48, Matheus de Oliveira wrote:
> I have made a small modification to keep the plans, and it got from
> 33957.768ms to 43782.376ms.

If I'm reading results.txt correctly, the avg runtimes are:

C and SPI_execute_with_args: 58567.708 ms
C and SPI_(prepare/keepplan/execute_plan): 43782.376 ms
C and heap_insert: 33957.768 ms

So switching to prepared plans helped quite a lot, but it's still slower 
than direct heap_inserts.

One thing that caught my eye:

> CREATE OR REPLACE FUNCTION partition_insert_trigger_spi()
> RETURNS trigger
> LANGUAGE C
> VOLATILE STRICT
> AS 'partition_insert_trigger_spi','partition_insert_trigger_spi'
> SET DateStyle TO 'ISO';

Calling a function with SET options has a fair amount of overhead, to 
set/restore the GUC on every invocation. That should be avoided in a 
performance critical function like this.

- Heikki


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