Re: Performance of the temporary table creation and use.

If you store the temp tables in RAM, how will you preserve the ACID
property on power failure (without using write-through which would
negate the speed advantage)?

The temp tables may be participating in a transaction.

-----Original Message-----
From: pgsql-hackers-owner(at)postgresql(dot)org
[mailto:pgsql-hackers-owner(at)postgresql(dot)org] On Behalf Of Luiz Gonzaga da
Mata
Sent: Tuesday, January 25, 2005 2:18 PM
To: pgsql-hackers(at)postgresql(dot)org
Subject: [HACKERS] Performance of the temporary table creation and use.

Hi,

A suggestion:

I made a test creating one database specific through pgAdminIII..
I created database test.
I created the table tb1 into test.

CREATE temporary TABLE tb1
(
campo1 int2 NOT NULL
)
WITH OIDS;

Insert into tb1 values(1);

The PostgreSQL creates a temporary schema pg_temp_(1-n). it physically

places the table in this temporary schema and with a OID inside of the

structure base/OID_do_database.

Although to have changed they sort_mem/work_mem it for 1 MB, it did not

use this area in available memory for the connection to make the
creation of the temporary table.

It has enough memory so that it was used. It would not be the case of

beyond create index, create temporary table also to use this available
resource? The performance would be another one in environments with
much competition., not?

This value of sort_mem/work_mem is configured and not used.

Regards,

Luiz Gonzaga da Mata

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