Re: Concurrence GiST - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Concurrence GiST
Date
Msg-id 23453.1072801555@sss.pgh.pa.us
Whole thread Raw
In response to Concurrence GiST  (Teodor Sigaev <teodor@sigaev.ru>)
List pgsql-hackers
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


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