Hi, > I tied using in-memory db doesn't improve the performance at all.
Did you read the performance docs yet - http://h2database.com/html/performance.html ? Specially the built-in profiler and indexes. > LOG=0, LOCK_MODE=0 and FILE_LOCK=NO has any effect on the performance? Not if indexes are missing, queries are slow and so on. LOG=0 might double performance, but that's it. lock mode and file lock don't typically improve performance, they are just dangerous. Regards, Thomas On Wed, Jan 30, 2013 at 8:53 PM, Sri <[email protected]> wrote: > I tied using in-memory db doesn't improve the performance at all. Both > in-memory and server have similar turn around times. > > I was looking at some of the H2 documentation and came across below one. > As I mentioned earlier DB is only for reads so by doing LOG=0, LOCK_MODE=0 > and FILE_LOCK=NO has any effect on the performance? > > "Some features are known to be dangerous, *they are only supported for > situations where performance is more important than reliability*. Those > dangerous features are: > > - Disabling the transaction log or FileDescriptor.sync() using LOG=0 > or LOG=1. > - Using the transaction isolation level READ_UNCOMMITTED (LOCK_MODE 0) > while at the same time using multiple connections. > - Disabling database file protection using (setting FILE_LOCK to NO in > the database URL). > - Disabling referential integrity using SET REFERENTIAL_INTEGRITY FALSE > ." > > > -Sri > > On Tuesday, November 13, 2012 7:32:35 PM UTC-8, Kartweel wrote: >> >> Other people might have some suggestions, but I guess if you try it on >> a solid state disk or just trial as an in memory database and see if it >> performs faster. >> >> Or you could also try it on a ram disk and see if it improves >> performance. That way you don't need to try any other hardware. >> >> At least then you'll know the disk was the bottleneck. >> >> Ryan >> >> On 14/11/2012 7:03 AM, Sri wrote: >> >> Sorry I was looking into some other things...now I got back to this.. >> >> How do we determine if disk io is capped? >> >> I do see disk io is varying (up and down from 40kb- 200kb and >> occasionally shoots up to 950kb) all the time when I observed windows >> resource monitor. >> >> -Sri >> >> On Friday, November 2, 2012 2:23:03 PM UTC-7, Kartweel wrote: >>> >>> Hi, >>> >>> Makes sense to me. If cpu isn't the issue (which I doubt it would be in >>> a database, but maybe the encryption adds a lot of overhead?) then adding >>> more threads would increase the time proportionally + synchronisation >>> overhead. Also there would be more work for the disk seeking between all >>> the different locations. >>> >>> So are you saying that disk io is increasing with each thread you add? >>> or is it capped? both bandwidth and iops ? >>> >>> On 3/11/2012 4:44 AM, Sri wrote: >>> >>> Disk IO looks good too...can't seem to find what is the issue... >>> >>> On Thursday, November 1, 2012 2:36:21 PM UTC-7, Kartweel wrote: >>>> >>>> How about disk io?, usually the disk is the bottleneck. >>>> >>>> On 2/11/2012 3:44 AM, Sri wrote: >>>> > Hi, >>>> > >>>> > I am running H2 DB in server mode and using it for read only. It's >>>> > been performing very good with single user/thread and the performance >>>> > is getting degraded as I add more concurrent users/threads. >>>> > >>>> > Single user/thread --> about 100ms >>>> > 10 users/threads --> about 230ms >>>> > 15 users/threads --> about 320ms >>>> > 20 users/threads --> about 440ms >>>> > 25 users/threads --> about 550ms >>>> > 40 users/threads --> about 900-1000ms >>>> > 50 users/threads --> about 1300-1400ms >>>> > >>>> > Please see the attached screenshot for CPU, heap and thread >>>> > monitoring. I do not see the problem of CPU being max out or not >>>> > enough memory or not scaling threads as I add more users. >>>> > >>>> > H2 Version:h2-1.3.166 >>>> > Url: >>>> > jdbc:h2:tcp://localhost:9092/<**<DB absolute >>>> > path>>;MULTI_THREADED=1;CACHE_**SIZE=<<cashesize>>;CIPHER=AES;**IFEXISTS=TRUE >>>> >>>> > >>>> > <<cashesize>> ==> tried different values, defualt-16mb, 128mb, 256mb, >>>> > 512mb and 1024mb (supplied in KB though) >>>> > >>>> > FYI, >>>> > Each thread is executing lot of queries (around 15-20) and some of >>>> > them are recursive queries (to fetch heirachy data). >>>> > >>>> > >>>> > Please let me know if anybody run into the same problem and how did >>>> > you resolve. >>>> > >>>> > Thanks in advance. >>>> > -Sri >>>> > -- >>>> > You received this message because you are subscribed to the Google >>>> > Groups "H2 Database" group. >>>> > To view this discussion on the web visit >>>> > https://groups.google.com/d/**msg/h2-database/-/hbZ9WV8cFWEJ<https://groups.google.com/d/msg/h2-database/-/hbZ9WV8cFWEJ> >>>> **. >>>> > To post to this group, send email to [email protected]. >>>> > To unsubscribe from this group, send email to >>>> > h2-database...@googlegroups.**com. >>>> > For more options, visit this group at >>>> > http://groups.google.com/**group/h2-database?hl=en<http://groups.google.com/group/h2-database?hl=en>. >>>> >>>> >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "H2 Database" group. >>> To view this discussion on the web visit https://groups.google.com/d/** >>> msg/h2-database/-/njQ5VJHkPvEJ<https://groups.google.com/d/msg/h2-database/-/njQ5VJHkPvEJ> >>> **. >>> To post to this group, send email to [email protected]. >>> To unsubscribe from this group, send email to >>> h2-database...@googlegroups.**com. >>> For more options, visit this group at http://groups.google.com/** >>> group/h2-database?hl=en<http://groups.google.com/group/h2-database?hl=en> >>> . >>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "H2 Database" group. >> To view this discussion on the web visit https://groups.google.com/d/** >> msg/h2-database/-/YscoajbGnT4J<https://groups.google.com/d/msg/h2-database/-/YscoajbGnT4J> >> **. >> To post to this group, send email to [email protected]. >> To unsubscribe from this group, send email to h2-database...@** >> googlegroups.com. >> For more options, visit this group at http://groups.google.com/** >> group/h2-database?hl=en<http://groups.google.com/group/h2-database?hl=en> >> . >> >> >> -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/h2-database?hl=en. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. 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