I can understand the performance loss on non-selects for keeping the
index validity state tracking the row validity, but would that outweigh the
performance gains on selects? Depends on your mix of selects to non
selects I guess, but other database systems seem to imply that keeping
the index on track is worth it overall.
Cheers,
Gary.
On 28 Apr 2004 at 15:04, Christopher Kings-Lynne wrote:
> > Why is there an entry in the index for a row if the row is not valid?
> > Wouldn't it be better for the index entry validity to track the row validity.
> > If a particular data value for a query (join, where etc.) can be satisfied
> > by the index entry itself this would be a big performance gain.
>
> For SELECTs, yes - but for INSERT, UPDATE and DELETE it would be a big
> performance loss.
>
> Chris
>
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
