On Fri, Apr 4, 2014 at 2:03 PM, Heikki Linnakangas <hlinnakan...@vmware.com>wrote:
> On 04/04/2014 02:53 PM, Rohit Goyal wrote: > >> Hi All, >> >> I was comparing postgresql performance and was just curious about >> performance in case i want to store the updated index tuple version on a >> different page. >> I was looking into the code of heapam.c, but was not able to find loop >> which i should remove so that postgresql use a different buffer for >> updated >> index tuple version. >> > > Did you mean to: > > 1. Force the old and new tuple to always be stored on different pages? > > Hack heap_update so that it chooses a new page. I think you'll also need > to hack RelationGetBufferForTuple to not return the same buffer. > > Can you explain a bit more from inside the code where i have to make the changes :)? my focus is just to store the index tuple of an updated tuple onto a different page or on a different buffer. > 2. Disable the HOT optimization, so that HOT is not used even if the old > and new tuple are stored on the same page? > > In heap_update, force satisfies_hot variable to false. > If I do change only this variable to false. then does it means, i have disabled the hot update.? > > 3. Allow HOT to be used even though the old and new tuple are stored on > different pages? > > This is not feasible.. > > - Heikki > thanks in advance.!! :) Regards, Rohit Goyal -- Regards, Rohit Goyal
