Re: [HACKERS] Priorities for 6.6

>
> > In short, if you load a bunch of tuples into a table, the first select
> > after the load can run a lot slower than you might expect, because it'll
> > be writing back most or all of the pages it touches.  But that penalty
> > doesn't affect every select, only the first one to scan a newly-written
> > tuple.
>
> I have removed this from the TODO list:
>
>    * Prevent fsync in SELECT-only queries

    I think this entry should stay.

    In   fact,  there  is  a  write  on  every  transaction  that
    commits/aborts even if it's one that doesn't modify any data.
    pg_log  is  written  for  SELECT  only  transactions too. I'm
    nearly 99.5% sure  that  not  fsync()'ing  those  transaction
    would not hit reliability and we might have to work it out.

    This  might  be  one cause that surrounding a bunch of SELECT
    statements by BEGIN/END speeds up PostgreSQL in non -F  mode.


Jan

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