Heikki Linnakangas <[EMAIL PROTECTED]> writes: > Florian G. Pflug wrote: >> * Note: xlog record is marked as outside transaction control, since we >> * want it to be redone whether the invoking transaction commits or not.
> That comment is a bit misleading, I agree. We don't skip xlog entries, > they're always replayed. Yeah, this distinction is another bit of effectively-dead code left over from Vadim's original plan of using WAL for UNDO. I haven't worried about ripping it out because it doesn't cost much and it seems that distinguishing transactional from nontransactional changes might be useful for log analysis if nothing else. > Yep, that's right. The reconstructed page is not always byte-to-byte > identical to the original. We don't worry about recovering cmin/cmax since only the originating transaction would have cared. I think physical location of tuples on a page isn't reliably reproduced either. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match