Re: Dynamic Partitioning using Segment Visibility Maps

On Thu, 2008-01-03 at 00:41 +0000, Sam Mason wrote:
> On Wed, Jan 02, 2008 at 05:56:14PM +0000, Simon Riggs wrote:
> > Like it?
> 
> Sounds good.  I've only given it a quick scan though.  Would read-only
> segments retain the same disk-level format as is currently?  

Yes, no changes at all to the table. So your app would just work,
without any DDL changes. Existing partitioning apps would not change.

> It seems
> possible to remove the MVCC fields and hence get more tuples per page---
> whether this would actually be a net performance gain/loss seems like
> a difficult question question to answer, it would definitly be a
> complexity increase though.

I've been looking at general compression at table and segment level, but
thats further down the track. Removing the MVCC fields is too much work,
I think.

> Reading this reminds me of the design of the store for a persistent
> operating system called EROS.  It has a very good paper[1] describing
> the design (implementation and careful benchmarking thereof) that I
> think could be a useful read.

Thanks, will do.

--  Simon Riggs 2ndQuadrant  http://www.2ndQuadrant.com