> 1. When I query the table by ID, it performs index scan on each
> partition. The result is only found in one partition, but I understand
> why it needs to look in all of them. How much disk reading does it
> involve? Is only the "head" of indexes for partitions that do not
> include the row scanned, or are always whole indexes read? I would
> like to know the general rule for index scans.
If you're not including the partition criterion in most of your queries,
you're probably partitioning on the wrong value.
--Josh Berkus