On Wed, Oct 30, 2013 at 9:23 AM, Leonardo Francalanci <m_li...@yahoo.it> wrote: >> LSM-trees seem patent free > > I'm no expert, and I gave it just a look some time ago: it looked to me very > complicated to get right... and as far as I remember you don't get that much > gain, unless you go multi-level which would complicate things further > >> Please somebody advise patent status of Y-trees otherwise I wouldn't bother. > > y-trees look much more easier to get right... (and to me they also make more > sense, but I'm not skilled enough to judge). > > There's also the FD-tree, which looks a lot like the (patented...) fractal > tree: > http://www.ntu.edu.sg/home/bshe/fdtree_pvldb.pdf
Skimming the white paper, it's clear right from the start that they make assumptions about the hardware that appear to be already obsolete -- extremely poor write performance vs read performance of SSD. Later generation SSDs are increasingly using hardware optimizations to convert random writes to sequential writes using various tricks. Point being: hardware is marching along pretty fast (after 20+ years of stagnation) and it's dangerous (IMO) to make big software investments based on the situation on the ground *today*. merlin -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
