ahh.... good point
Thanks
On 9/22/06, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Alex Turner" <armtuk(at)gmail(dot)com> writes:
> > Home come the query statistics showed that 229066 blocks where read
> given
> > that all the blocks in all the tables put together only total 122968?
>
> You forgot to count the indexes. Also, the use of indexscans in the
> mergejoins probably causes multiple re-reads of some table blocks,
> depending on just what the physical ordering of the rows is.
>
> regards, tom lane
>