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 
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