> it will probably be better to denormalize and store > some precomputed data
Yes, if you know there are queries you need to serve it is better to support those directly in the data model. Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 22 Jun 2011, at 23:52, Wojciech Pietrzok wrote: > OK, got some results (below). > 2 nodes, one on localhost, second on LAN, reading with > ConsistencyLevel.ONE, buffer_size=512 rows (that's how many rows > pycassa will get on one connection, than it will use last row_id as > start row for next query) > > Queries types: > 1) get_range - just added limit of 1024 rows > 2) get_indexed_slices ASCII - one term: on indexed column with ASCII type > 3) get_indexed_slices INT - one term: on indexed column with INT type > 4) get_indexed_slices ASCII + GTE, LTE on indexed INT - three terms: > on indexed column with INT type + LTE, GTE on indexed column with INT > type > 5) get_indexed_slices 2 terms, ASCII - two terms, both columns > indexed, with ASCII type > 6) get_indexed_slices ASCII + GTE, LTE on non indexed INT - like 4) > but LTE, GTE are on non-indexed column > > 3 runs for each set of queries, on successive runs times were better. > Times are in seconds > > > But if you say that 1024 rows is reasonably big slice (not mentioning > over 10k rows) it will probably be better to denormalize and store > some precomputed data > > > Results: > > # Run 1 > PERF: [a] get_range: 0.58[s] > PERF: [a] get_indexed_slices ASCII: 3.96[s] > PERF: [a] get_indexed_slices INT: 1.82[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT: 1.31[s] # > 314 returned > PERF: [cr] get_indexed_slices ASCII: 1.13[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 8.69[s] > > # Run 2, same queries > PERF: [a] get_range: 0.33[s] > PERF: [a] get_indexed_slices ASCII: 0.36[s] > PERF: [a] get_indexed_slices INT: 5.39[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT : 5.42[s] # > 314 returned > PERF: [cr] get_indexed_slices ASCII: 0.55[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 3.57[s] > > # Run 3, same queries > PERF: [a] get_range: 0.18[s] > PERF: [a] get_indexed_slices ASCII: 0.39[s] > PERF: [a] get_indexed_slices INT: 0.83[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT : 0.85[s] # > 314 returned > PERF: [cr] get_indexed_slices ASCII: 0.39[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 3.36[s] > > # changed some terms, so always 1024 returned are returned > # Run 1 > PERF: [a] get_range: 0.31[s] > PERF: [a] get_indexed_slices ASCII: 3.14[s] > PERF: [a] get_indexed_slices INT: 0.70[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT : 4.72[s] > PERF: [cr] get_indexed_slices ASCII: 0.73[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 0.85[s] > PERF: [cr] get_indexed_slices ASCII + GTE, LTE on non indexed INT : 2.17[s] > > # Run 2, same queries > PERF: [a] get_range: 0.20[s] > PERF: [a] get_indexed_slices ASCII: 0.60[s] > PERF: [a] get_indexed_slices INT: 1.22[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT : 1.27[s] > PERF: [cr] get_indexed_slices ASCII: 0.48[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 0.50[s] > PERF: [cr] get_indexed_slices ASCII + GTE, LTE on non indexed INT : 2.22[s] > > # Run 3, same queries > PERF: [a] get_range: 0.25[s] > PERF: [a] get_indexed_slices ASCII: 0.44[s] > PERF: [a] get_indexed_slices INT: 0.89[s] > PERF: [a] get_indexed_slices INT + GTE, LTE on indexed INT : 6.58[s] > PERF: [cr] get_indexed_slices ASCII: 1.18[s] > PERF: [cr] get_indexed_slices 2 terms, ASCII: 0.50[s] > PERF: [cr] get_indexed_slices ASCII + GTE, LTE on non indexed INT : 2.09[s] > > > > > 2011/6/21 aaron morton <aa...@thelastpickle.com>: >> Can you provide some more information on the query you are running ? How >> many terms are you selecting with? >> >> How long does it take to return 1024 rows ? IMHO thats a reasonably big >> slice to get. >> >> The server will pick the most selective equality predicate, and then filter >> the results from that using the other predicates. >> >> Cheers > > > -- > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > KosciaK mail: kosci...@gmail.com > www : http://kosciak.net/ > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
