Robert Haas <robertmhaas@gmail.com> writes:
> On a straight pgbench -S test, you get four system calls per query:
> recvfrom(), lseek(), lseek(), sendto(). Adding -M prepared eliminates
> the two lseeks.
[ scratches head... ] Two? Is that one for the table and one for its
lone index, or are we being redundant there?
(If the query ended up being a seqscan, I'd expect a second
lseek(SEEK_END) when the executor starts up, but I gather from the other
complaints that the mosbench people were only testing simple indexscan
queries.)
regards, tom lane