Hi, Alvaro,
Alvaro Herrera wrote:
>> Additionally, in most UPDATE cases, the new row version will fit into
>> the same page as the old version. In this case, the index does not have
>> to be changed, which is an additional speed improvement.
> Actually, when the UPDATE puts a new row version in the same heap page,
> the index must be updated anyway.
AFAICS only, when the index covers (directly or via function) a column
that's actually changed.
Changing columns the index does not depend on should not need any write
access to that index.
Correct me if I'm wrong.
Thanks,
Markus
--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf. | Software Development GIS
Fight against software patents in Europe! www.ffii.org
www.nosoftwarepatents.org