Slow inserts after a while? Can you create some test code to demonstrate this?
H2 does perform an automatic ANALYZE on a table periodically following an insert, which causes a measurable delay. But this does not happen for every 5th row. On Sep 7, 2:54 pm, Navjot Singh <[email protected]> wrote: > Hi, > > I tried setting up WRITE_DELAY to 30000 but I still get those slow > inserts approx every 500ms. > > Is there something I am missing completely? > > regards > Navjot Singh > > On Sep 6, 5:44 pm, Noel Grandin <[email protected]> wrote: > > > > > > > > > See here:http://h2database.com/html/advanced.html > > the discussion on durability. > > > WRITE_DELAY sets the delay between writes being committed to disk. > > > You could set it to longer, and you will gain more performance on > > average, but risk losing more data if you have a power failure. > > > On Tue, Sep 6, 2011 at 16:10, Navjot Singh <[email protected]> wrote: > > > Hi, > > > > Can anyone explain a bit more about this option - what it exactly > > > achieves? > > > > SET WRITE_DELAY > > > > regards > > > Navjot Singh > > > > On Sep 6, 9:51 am, Navjot Singh <[email protected]> wrote: > > >> Hi, > > > >> I read some posts on the 'slow insert performance' reported by others > > >> but couldnt seem to figure out an approach to improve on this. Just > > >> wanted to share my problem and pick some brains about how others > > >> solved their problem and may offer some tips. > > > >> In my use case, there is a ever running process which does some > > >> analytics and keep generating the output data. This output data we > > >> save in H2 (version 1.3.157). We are using mixed mode as we got 2 > > >> processes writing to same database. > > >> The database file is lying on the shared network drive but fast r/w > > >> otherwise. Cache is 64MB. We use connection pool and a db close delay > > >> of 5s and rest all is default. > > > >> I have noticed that upto ~80k rows, the insert perf is fast, hardly > > >> touches a ms but then gradually becomes slow. After that, > > >> approximately every 5th insert operation (or one about every half a > > >> sec) seems to be taking on an avg of 300ms while others keep inserting > > >> in about a 1 ms or less time. So with my shallow knowledge of H2, it > > >> seems that inserts shall be okay, there is something else happening > > >> within H2 at regular interval which is causing this extra time. > > > >> What could be the possible cause? Please help me understand this. Is > > >> there some file operation that H2 is doing which can cause them to be > > >> slow as I read about some sync() being slow. > > > >> I have profiled our application which doesnt seem to be contributing > > >> to this behavior. > > > >> regards > > >> Navjot Singh > > > > -- > > > 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 > > > athttp://groups.google.com/group/h2-database?hl=en.-Hide quoted text - > > > - Show quoted text - -- 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.
