Dmitriy, Time ago we've tested SkipList index implementation which is not snapshotable against our SnapTree and we did not notice any speedups.
Sergi 2015-09-17 6:31 GMT+03:00 Dmitriy Setrakyan <[email protected]>: > > > On Thu, Sep 17, 2015 at 2:58 AM, Alexey Kuznetsov <[email protected] > > wrote: > >> If it is not snapsohtable there could be at least one use-case: populated >> once and never changed cache. >> For example for some analytics. >> User populate 100500 entries into cache, build index and run 100500 >> queries. >> >> > I agree with Alexey. If disabling snapshots provides any kind of > performance optimization for us, we should probably support 2 modes, > snapshotttable and not, at least at configuration level. I am sure that > there are plenty of users that don't care about snapshots, even in the > presence of concurrent updates. > > From the feature standpoint, I don't see anything in CQEngine that Ignite > does not have in its SQL queries. However, from the performance standpoint, > I still think that it is worthwhile to check out the CQ Engine code and see > if we there is anything we can borrow. > > > >> On Thu, Sep 17, 2015 at 6:27 AM, Sergi Vladykin <[email protected] >> > wrote: >> >>> Thanks for the pointers! >>> The main difficulty at Ignite side is that we need >>> index data structure to be snapshotable with O(1) complexity and of >>> course >>> without copying of the whole thing, so I'm not sure if we will be able >>> to use something from there as is. >>> But nevertheless CQEngine at least deserves to be investigated for ideas >>> about data structures. >>> >>> Sergi >>> >>> >>> 2015-09-17 1:19 GMT+03:00 vkulichenko <[email protected]>: >>> >>>> javadevmtl wrote >>>> > Yeah it's perforamance is crazy. I hadn't experienced any "buggy" >>>> issues >>>> > when i tried. it also has off-heap otion now also. But I find the >>>> concept >>>> > of O(1) indexes very interesting... >>>> >>>> I think that O(1) is achievable only for hash indexes and therefore can >>>> be >>>> used only for equality queries. This is a very rare case in SQL and can >>>> barely be treated as a replacement of tree indexes. >>>> >>>> -Val >>>> >>>> >>>> >>>> -- >>>> View this message in context: >>>> http://apache-ignite-users.70518.x6.nabble.com/Btw-anyone-heard-of-CQ-engine-tp1421p1425.html >>>> Sent from the Apache Ignite Users mailing list archive at Nabble.com. >>>> >>> >>> >> >> >> -- >> Alexey Kuznetsov >> GridGain Systems >> www.gridgain.com >> > >
