"Zeugswetter Andreas DAZ SD" <[EMAIL PROTECTED]> writes: > I think I recall that lseek may have a negative effect on some OS's > readahead calculations (probably only systems that cannot handle an > lseek to the next page eighter) ? Do you think we should cache the > last value to avoid the syscall ?
We really can't, since the point of doing it is to find out whether any other backends have extended the file since we last looked. Also, IIRC seqscan startup does a similar lseek() anyhow, so having the planner do one will make no difference to the readahead or lack of it in a subsequent seqscan. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings