From: | Mark Lewis <mark(dot)lewis(at)mir3(dot)com> |
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To: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
Cc: | Scott Marlowe <smarlowe(at)g2switchworks(dot)com>, Karen Hill <karen_hill22(at)yahoo(dot)com>, pgsql-performance(at)postgresql(dot)org |
Subject: | Re: How long should it take to insert 200,000 records? |
Date: | 2007-02-06 19:10:53 |
Message-ID: | 1170789053.16656.486.camel@archimedes |
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Lists: | pgsql-performance |
On Tue, 2007-02-06 at 14:06 -0500, Merlin Moncure wrote:
> On 2/6/07, Mark Lewis <mark(dot)lewis(at)mir3(dot)com> wrote:
> > > actually, I get the stupid award also because RI check to unindexed
> > > column is not possible :) (this haunts deletes, not inserts).
> >
> > Sure it's possible:
> >
> > CREATE TABLE parent (col1 int4);
> > -- insert many millions of rows into parent
> > CREATE TABLE child (col1 int4 REFERENCES parent(col1));
> > -- insert many millions of rows into child, very very slowly.
>
> the database will not allow you to create a RI link out unless the
> parent table has a primary key/unique constraint, which the database
> backs with an index....and you can't even trick it afterwards by
> dropping the constraint.
>
> it's the other direction, when you cascade forwards when you can have
> a problem. this is most common with a delete, but can also happen on
> an update of a table's primary key with child tables referencing it.
>
Hmmm, should check my SQL before hitting send I guess. Well, at least
you no longer have to wear the stupid award, Merlin :)
-- Mark Lewis
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