What's the batch size for postgresql ? What's the size of one entry ? Could you provide the test code for both postgres and Ignite (just the query + read with the time estimation) ?
2016-05-25 11:13 GMT+03:00 Tomek W <rrrtomtom...@gmail.com>: > | How many entries are downloaded to the client in both cases? > 3000 000 > > | Do the both queries involve network I/O ? > No, I have only local one server (for testing purpose). > > > 2016-05-25 9:59 GMT+02:00 Alexei Scherbakov <alexey.scherbak...@gmail.com> > : > >> SELECT * is not really a good test query. >> It's result can be affected not only by engine performance. >> >> How many entries are downloaded to the client in both cases? >> Do the both queries involve network I/O ? >> >> 2016-05-25 7:58 GMT+03:00 Denis Magda <dma...@gridgain.com>: >> >>> In general Ignite is designed to be used in a distributed environment >>> when gigabytes or terabytes of dataset is spread across many cluster nodes >>> and SQL queries executed across the cluster should be faster since >>> resources of all the machines will be used and as a result a query should >>> be completed quicker. In your scenario you just have only a single cluster >>> node and in fact comparing performance of PostgreSQL and H2 (engine that is >>> used by Ignite SQL) and I can consider that Ignite SQL can work slightly >>> slowly but this in is not Ignite usage scenario. >>> >>> However if you try to create a cluster of several nodes running on >>> different physical machines, pre-load gigabytes of data there and compare >>> Ignite SQL and PostgresSQL you should see performance improvements on >>> Ignite side. >>> >>> In any case taking into account the advise above do the following: >>> - execute “EXPLAIN” query to see that the index is chose properly [1]; >>> - H2 console will allow you to see how fast a query is presently >>> executed on a single node removing several Ignite layers [2]; >>> - check if you have any GC pauses during query execution since it can >>> affect execution time [3] >>> >>> Also share the objects you use as keys and values. >>> >>> [1] https://apacheignite.readme.io/docs/sql-queries#using-explain >>> [2] >>> https://apacheignite.readme.io/docs/sql-queries#using-h2-debug-console >>> [3] >>> https://apacheignite.readme.io/v1.6/docs/jvm-and-system-tuning#section-detailed-garbage-collection-stats >>> >>> — >>> Denis >>> >>> On May 25, 2016, at 3:23 AM, Tomek W <rrrtomtom...@gmail.com> wrote: >>> >>> >>> +==============================================================================================+ >>> | Node ID8(@), IP | CPUs | Heap Used | CPU Load | Up Time >>> | Size | Hi/Mi/Rd/Wr | >>> >>> +==============================================================================================+ >>> | 0F0AAF99(@n0), 127.0.0.1 | 8 | 54.50 % | 3.23 % | 00:13:13:49 | >>> 3000000 | Hi: 0 | >>> | | | | | >>> | | Mi: 0 | >>> | | | | | >>> | | Rd: 0 | >>> | | | | | >>> | | Wr: 0 | >>> >>> +----------------------------------------------------------------------------------------------+ >>> >>> >>> I followed your hints. Actually, client doesn't require such many >>> memory as before - thanks for it. >>> >>> >>> When it comes to configuration of server, I also followed your hints, >>> results: >>> >>> Querying is done by JDBC Client. In ignite and postgresql I have single >>> index on column A. >>> >>> Ignite: SELECT * FROM table WHERE A > 1345 takes 6s. >>> Postgres: SELECT * FROM table WHERE A > 1345 takes 4s. >>> >>> As you can see, postgres is still bettter than Ignite. I show you >>> significant fragments of my configuration: >>> http://pastebin.com/EQC4JPWR >>> >>> And xml for server file: >>> http://pastebin.com/enR9h5J4 >>> >>> >>> Try to consider why postgresql is still better, please. >>> >>> >>> >> >> >> -- >> >> Best regards, >> Alexei Scherbakov >> > > -- Best regards, Alexei Scherbakov
