Hi, There is already such a cache in H2. I suggest to test it. If it doesn't work as expected, please provide more details about your use case.
Regards, Thomas On Wed, Mar 27, 2013 at 7:41 PM, Mike Funaro <[email protected]> wrote: > Hi Navjot, > > Thanks for the response. A little background on the application that I am > writing. Currently there is a solution in place that uses flat file with > optimized access, meaning there is a whole access mechanism built around > these flat files to make accessing them lightning fast. However this > technology is getting long in the tooth and does not allow us easy access > to the data in human readable format or the ability to run queries on the > data. What I am trying to do is replace those flat files with an embedded > database, however, I need to match those flat files in access speed to have > this new solution be viable in our current model. > > What I have tried so far... > > 1. I increased the CACHE_SIZE but this did not seem to affect the speed of > the application. Our queries are very very simple select queries. > 2. I implemented an application level caching system. Before going to the > DB, the application checks the cache to see if that query has been run > before, if so it uses the value stored in the cache. > > The caching system speeds up the application quite a bit, but since I am > trying to replace a system already in place, that does not use caching, I > view this as a sort of cheat to beat the old system. What I really want to > do is optimize the H2 database so that I can match the speeds of > the current flat file solution on reads. > > Could you elaborate a bit more on your suggestion #1? Our DB is going to > be read-only at all times, we don't insert or update any rows. The DB file > is created and populated via another program prior to this application. > > What I was basically after was a caching mechanism similar to the one I > put in the application level but on the DB level and after much googling > around yesterday it seems that is not offered by H2 or even any embedded DB > solution. > > Thanks for taking a look and for the response. > > -Mike > > > On Tuesday, March 26, 2013 5:32:40 PM UTC-4, Navjot Singh wrote: > >> Hi, >> >> >> >> The answer can vary a lot. Also, the relevant cache requirement should be >> -- its not the same query, but the result set that the query is going to >> return remain same/similar or not. >> >> >> >> 1. As you are running in embedded mode, first Q I ask is what kind >> of disk are you writing to. If you are writing to RAM disk, then it’s >> already in memory for you. If not, then can you think of it as one option. >> >> 2. If the above is not an option, next option could be setup >> CACHE_SIZE. This should depend upon the size of data that your query needs >> to churn through to produce your result set. This can eat up your heap but >> if you have enough memory, this might be an option. >> >> 3. If you know the result set is going to be same for some time >> then you can setup read-thru cache yourself in simple map based cache with >> TTL set to expire as per you app requirement. Or use any caching framework. >> There are so many. >> >> >> >> HTH >> >> Navjot Singh >> >> >> >> *From:* [email protected] [mailto:h2-da...@**googlegroups.com] *On >> Behalf Of *Mike Funaro >> >> *Sent:* 26 March 2013 19:45 >> *To:* [email protected] >> *Subject:* Cache query results? >> >> >> >> HI Everyone, >> >> >> >> I started using H2 as an alternative to Derby because of the tremendous >> speeds. I am using it in embedded mode. For my application, there is >> a possibility of having the same SELECT query run time after time, is there >> any kind of mechanism to cache those query results so that another SELECT >> query would not have to be run? >> >> >> >> If you need more details about how my application operates I would be >> happy to elaborate. >> >> >> >> Thanks, >> >> Mike >> >> >> >> >> >> -- >> 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 h2-database...@**googlegroups.com. >> To post to this group, send email to [email protected]. >> >> Visit this group at >> http://groups.google.com/**group/h2-database?hl=en<http://groups.google.com/group/h2-database?hl=en> >> . >> For more options, visit >> https://groups.google.com/**groups/opt_out<https://groups.google.com/groups/opt_out> >> . >> >> >> >> -- > 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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