On Thu, 2007-02-22 at 20:07 -0600, Andrew Dunstan wrote: > Simon Riggs wrote: > > > > I propose that at CREATE TABLE time, the column ordering is re-ordered > > so that the table columns are packed more efficiently. This would be a > > physical re-ordering, so that SELECT * and COPY without explicit column > > definitions would differ from the original CREATE TABLE statement. > > > > This would be an optional feature, off by default, controlled by a > > USERSET GUC > > optimize_column_order = off (default) | on > > > > > Umm, you want a GUC setting to enable standards-breaking behaviour and > that will be obsolete when we do column ordering right, which is not > likely to be more than one release away, and could even still happen in > this coming release?
If this is standards-breaking as you say, I would withdraw immediately. I checked the SQL standard and could not see how this would do so. The standard states SELECT * would return columns in order; it doesn't say what that order should be, nor does CREATE TABLE enforce the ordering to be the same as it has specified, AFAICS. Please correct me and I will withdraw. Practical issues seem far stronger drivers than standards issues here, which is why the parameter would default=off. If the full implementation exists and works, I would welcome it. This proposal is really aimed at what we do if that doesn't occur; we must wait to see if it will. I see that many users would want to get something sooner rather than later. That isn't a commercial perspective, I see that as a PostgreSQL advocacy perspective. I also see that we are forcing change into the on-disk format of heaps in this release. If we defer this to another release then we would be effectively changing the on-disk format again in next release. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
