Teodor Sigaev <teodor@sigaev.ru> writes:
> I can use NSN (node sequence number) and I find recommendation to use
> LSN (WAL log sequence number) as NSN. NSN must be stored in page and I
> found that page (PageHeaderData struct) already has XLogRecPtr for
> storing LSN. My question is: who is manage this field? Is it filled
> automatically or I should write code to manage it?
It must be set just after you emit a WAL record for any action affecting
the page. Take a look at the btree code for WAL (look for XLogInsert
and PageSetLSN calls). Also I'd suggest reading the WAL section of
access/nbtree/README.
regards, tom lane