Tom,
> We have also talked about solving the multi-column statistics problem
> (which, at its core, is "which combinations of columns are worth
> accumulating stats for?" --- you can't possibly store stats for every
> combination!) by having what would amount to hints from the DBA saying
> "keep s
Tom Lane wrote:
> We have also talked about solving the multi-column statistics problem
> (which, at its core, is "which combinations of columns are worth
> accumulating stats for?" --- you can't possibly store stats for every
> combination!) by having what would amount to hints from the DBA sayin
Casey Duncan <[EMAIL PROTECTED]> writes:
> Yes, but it may be much more efficient for the human to tell the
> computer than for the computer to introspect things. Take, for
> example, ndisinct as data grows large.
Yeah, an override estimate for a column's ndistinct seems a perfect
example of t
On Oct 12, 2006, at 4:26 AM, Andrew Sullivan wrote:
On Thu, Oct 12, 2006 at 08:34:45AM +0200, Florian Weimer wrote:
Some statistics are very hard to gather from a sample, e.g. the
number
of distinct values in a column.
Then how can the DBA know it, either? The problem with this sort of
a
