On Sun, Nov 09, 2008 at 11:02:32AM -0500, Tom Lane wrote: > Yes it would :-(. Also, this scheme would point us towards maintaining > the CRCs *continually* while the page is in memory, rather than only > recalculating them upon write. So every tuple insert/update/delete > would require a recalculation of the entire page CRC.
I wasn't thinking of that. I was thinking more of the situation where a seq scan reads in a page, updates a few hint bits and then goes on to the next page. For these just doing a few XORs might be cheaper. > What happened to the plan to double-buffer the writes to avoid this > issue? Might be better anyway. A single copy-and-checksum would probably be quite cheap (pulling the page into L2 cache). Have a nice day, -- Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/ > Please line up in a tree and maintain the heap invariant while > boarding. Thank you for flying nlogn airlines.
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