Hi Thomas, Thanks for your reply, it's really useful info.
One more thing: Is it possible with the page store to retrieve statistics on disk reads and writes (preferably number of pages, but number of bytes would also be OK?). I used to query for SELECT * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME = 'info.FILE_DISK_WRITE' ORDER BY NAME ASC; SELECT * FROM INFORMATION_SCHEMA.SETTINGS WHERE NAME = 'info.FILE_DISK_READ' ORDER BY NAME ASC; And count the differences before and after each statement so I knew how much data was read or written during execution of the statement. These seem to be not in use anymore since the DiskFile is now sort of deprecated. Is there any way to obtain this information? It should be possible to construct a trace and analyze the trace, but i'm interested in these statistics per statement and not in total. I can see that PageStore.java contains a writeCount, but i am not sure whether this contains the information I am looking for. Thanks, Sven On 11 okt, 10:22, Thomas Mueller <[email protected]> wrote: > Hi, > > > - Does H2 use paging by default? If not, is it possible to use this? > > The 'page store' storage engine (PageStore.java) is now used by > default in version 1.2.x. Before that, another algorithm is used > (DiskFile.java). I guess the page store is more interesting for you > (it is also faster). > > > - What is the default page size used (assuming paging is used to store > > data on disk). > > Currently 2 KB. > > > - Are there any guidelines somewhere about checking out the source > > code in an IDE (I use Eclipse). > > Seehttp://www.h2database.com/html/build.html > > > - How does H2 behave when using a cache size of 0? > > You can set the cache size to zero, but there will still be a small > cache (16 items or so). > > > it's for running > > some experiments for my master's project, and I'm trying to force the > > system into swapping from and to disk, counting the number of I/O > > operations in the process). > > Modern software is not optimized for this scenario, because there is > always a lot of memory available (more than 1 MB). I guess older > software behaves better (but worse if there _is_ a lot of memory). > > Regards, > Thomas --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/h2-database?hl=en -~----------~----~----~----~------~----~------~--~---
