On Friday 03 October 2008 09:03, I wrote: > Once we have the extent, we probe into the btree, 64 blocks below the > beginning of the extent, which ensures that no existing extents that > may overlap the io extent are missed...
...and I should mention, this constitutes a small efficiency that can be easily corrected. Each btree leaf pointer simply needs to have a bit reserved to indicate that some extents may overlap into the next btree leaf, and we check that bit during the probe to determine whether to seek directly to the target extent address, or to the predecessor node. This is the strategy used by HTree, and is one of the unique elements of HTree that distinquishes it from a standard BTree. This "continuation" bit is to be implmented in the generic btree code so that all the Tux3 btree flavors can take advantage of it, and therefore will be a step in the direction of implementing HTree and PHTree for tux3. Regards, Daniel _______________________________________________ Tux3 mailing list Tux3@tux3.org http://tux3.org/cgi-bin/mailman/listinfo/tux3
