Re: Global Sequences

On Tuesday, October 16, 2012 02:58:11 PM Andrew Dunstan wrote:
> On 10/16/2012 08:54 AM, Peter Eisentraut wrote:
> > Option 4 is of course to use UUIDs.
> 
> Yeah, I was wondering what this would really solve that using UUIDs
> wouldn't solve.

Large indexes over random values perform notably worse than mostly/completely 
ordered ones as they can be perfectly packed. Beside the fact that uuids have 
2/4 times the storage overhead of int4/int8.

That has influences both in query and modification performance.

Also, not allowing plainly numeric pk's makes porting an application pretty 
annoying...

Greetings,

Andres
-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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