You are welcome to modify the source code and try out your ideas. Instructions are here: http://h2database.com/html/build.html
On Tue, Nov 29, 2011 at 12:53, andreis <[email protected]> wrote: > >> As Noel suggest, you could split the table in two: one only contains the >> columns that are used a lot, and the other table for the remaining columns. > > Yes, I've thought about that solution. I even thought about > possibility to store the data as one-columnt-per-table. But I'm not > sure about performance of left joins on 20-30 tables. > > And my 2 cents on lazy fields initialization. I'm thinking about > simplier solution: > on our data set when reading almost all time is spent on converting to > string (ValueString.get(readString())). What about implementing a > LazyValue, which is initialized with pointers to the page (should be > possible if pages are immutable, of course), and start position. > Method `org.h2.result.Row.getValue` can initialize it just in time and > replace a lazy value with a real one. I think, it could give some > benefits not only for indexing large volumes of data, but for updates > when most fields of a row are unchanged and the h2 engine can reuse > binary representation of them without instantiating the real objects. > > Also, as I mentioned those batch inserts are implemented using a lot > of single insert statements. Is it possible to leveradge the batch? > For example, to write a log record for the batch at once? > Also, afair, databases along with providing smth like `WRITE_DELAY`, > have a parameter like the maximum size of not flushed log. I believe, > It's one page in H2 now. I think, writing of several pages at once is > faster then one by one. > Also, I wonder why temporary files for large selects (> > MAX_MEMORY_ROWS) and undo records are always created in a DB > directory? Would it make sense to place such files onto a fast storage > (like tmpfs)? > > -- > 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. > -- 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.
