On Mon, Jun 17, 2013 at 1:22 PM, Soroosh Sardari <soroosh.sard...@gmail.com>wrote:
> Hey > > I was reading the multi transaction log manager, multixact.c. > I didn't get what SLRU does. > > I want the goal of this module, and why we use it. > I'm kind of newbie, be patient with me ;) > > Did you look at src/backend/access/transam/slru.c ? The first para in that file is quite explanatory: * We use a simple least-recently-used scheme to manage a pool of page * buffers. Under ordinary circumstances we expect that write * traffic will occur mostly to the latest page (and to the just-prior * page, soon after a page transition). Read traffic will probably touch * a larger span of pages, but in any case a fairly small number of page * buffers should be sufficient. So, we just search the buffers using plain * linear search; there's no need for a hashtable or anything fancy. * The management algorithm is straight LRU except that we will never swap * out the latest page (since we know it's going to be hit again eventually). Thanks, Pavan -- Pavan Deolasee http://www.linkedin.com/in/pavandeolasee
