Re: Global Sequences - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Global Sequences
Date
Msg-id CA+U5nMJaEQtedAnrEmEGzCqc2jhztcAg=vLd8fmP-WonWjVRkQ@mail.gmail.com
Whole thread Raw
In response to Re: Global Sequences  (Christopher Browne <cbbrowne@gmail.com>)
List pgsql-hackers
On 16 October 2012 03:03, Christopher Browne <cbbrowne@gmail.com> wrote:

> There's a necessary trade-off; you can either have it globally
> *strongly* ordered, and, if so, you'll have to pay a hefty
> coordination price, or you can have the cheaper answer of a weakly
> ordered sequence.  The latter leaves me feeling rather "meh."

Oracle allows you to define whether you want ORDER or not for a
sequence when used in clustered mode.

Requesting a sequence to be strongly ordered across a generic
distributed system is very much like asking performance=none and
high_availability=off, which is why I didn't suggest it. So you're
right about the "hefty coordination price" but our conclusions differ
because of our understanding of that price.

I don't think it makes sense to spend the time implementing that option.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services



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