DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition;
	b=hQ6tJwmUelnuRR12r8bOMaRuV7I2aLtGQi8IH4nkAQm6QXansr5BRUWQyxTt925Fu5od4GKxFFBnP4GBTLVGPQfpb5FT7B0euw05oqDUcl1KANz2e8AWIEFerOeXIub+Tp5dMQmOCvD//ks/LNTMUnYDjoVrv5NbwnRKvYU28+A=
Message-ID: <5d0f60990610081404s79a90cdbha4603c70c75ce233@mail.gmail.com>
Date: Sun, 8 Oct 2006 23:04:02 +0200
From: "Dirk Jagdmann" <jagdmann@gmail.com>
To: pgsql-sql@postgresql.org
Subject: optimal insert
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

Hello experts,

I have a database that contains three tables:

create table a (
  id serial primary key,
  ... -- some more fields not relevant for my question
);
create table b (
  id serial primary key,
  ... -- some more fields not relevant for my question
);
create table a_b (
  a int not null references a,
  b int not null references b
);

Tables a and b have already been filled with lots of rows. Now my
application needs to insert the relationship of a to b into table a_b
and is currently doing it with inserts like the following:

insert into a_b(a,b) values(1,100);
insert into a_b(a,b) values(1,200);
insert into a_b(a,b) values(1,54);
insert into a_b(a,b) values(1,4577);

So for a batch of inserts the value of a stays the same, while for by
arbitrary values are inserted. Now I have wondered if PostreSQL offers
a smarter way to insert those values? A solution can contains usage of
some plpgsql code.

-- 
---> Dirk Jagdmann
----> http://cubic.org/~doj
-----> http://llg.cubic.org