Clarification - I used an MMap'd index and warmed it up with similar queries, as well as running the identical query many times before starting measurements. I had ample heap space.
Sriram. On Wed, Jul 24, 2013 at 9:11 AM, Sriram Sankar <san...@gmail.com> wrote: > I did some performance tests on a real index using a query having the > following pattern: > > termA AND (termB1 OR termB2 OR ... OR termBn) > > The results were not good and I was wondering if I may be doing something > wrong (and what I would need to do to improve performance), or is it just > that the OR is very inefficient. > > The format for the data below is illustrated below by example: > > 5|10 > time: 0.092728962; scored: 18 > > Here, n=5, and we measure performance for retrieval of 10 results which is > 0.0927ms. Had we not early terminated, we would have obtained 18 results. > > As you will see in the data below, the performance for n=0 is very good, > but goes down drastically as n is increased. > > Sriram. > > > 0|10 > time: 0.007941587; scored: 10887 > > 0|1000 > time: 0.018967384; scored: 10887 > > 0|5000 > time: 0.061943552; scored: 10887 > > 0|10000 > time: 0.115327001; scored: 10887 > > 1|10 > time: 0.053950965; scored: 0 > > 5|20 > time: 0.274681853; scored: 18 > > 10|10 > time: 0.14251254; scored: 22 > > 10|20 > time: 0.282503313; scored: 22 > > 20|10 > time: 0.251964067; scored: 32 > > 20|30 > time: 0.52860957; scored: 32 > > 50|10 > time: 0.888969702; scored: 57 > > 50|30 > time: 1.078579956; scored: 57 > > 50|50 > time: 1.601169195; scored: 57 > > 100|10 > time: 1.396391061; scored: 79 > > 100|40 > time: 1.8083494; scored: 79 > > 100|80 > time: 2.921094513; scored: 79 > > 200|10 > time: 2.848105701; scored: 119 > > 200|50 > time: 3.472198462; scored: 119 > > 200|100 > time: 4.722673648; scored: 119 > > 400|10 > time: 4.463727049; scored: 235 > > 400|100 > time: 6.554119665; scored: 235 > > 400|200 > time: 9.591892527; scored: 235 > >
