Re: a few crazy ideas about hash joins

On 2009-04-03, Simon Riggs <simon@2ndQuadrant.com> wrote:
>
> On Fri, 2009-04-03 at 18:03 +0100, Greg Stark wrote:
>
>> I wonder if we need a whole class of index algorithms to deal
>> specifically with read-only tables
>
> I think we can drop the word "index" from the sentence as well.
>
> "Read-only" isn't an isolated case. Often you find many read-only tables
> alongside rapidly changing tables. So even the busiest of databases can
> benefit from read-only optimisations. So I want MVCC *and* read only,
> not MVCC everywhere (or MVCC nowhere if customer changes horses to get
> read-only benefits elsewhere).
>
> Having changes to those tables cause much heavier additional work is OK,
> if judged on a cost/benefit basis. So the case I care about ought to be
> called "read-mostly" but we're talking write:read ratios of millions:1.

For the record and in case anyone gets interested in following up the
idea of "read only" tables, see also:

http://thread.gmane.org/gmane.comp.db.postgresql.devel.general/76366